It appears that since I don’t follow Patheos that I miss out on a lot of stuff, but the address towards whether ancient religious imagery can be appropriated or not was one that I found rather curious and spent the better part of the last hour contemplating. My response ended up being yes and no, and really the line between them is pretty fine and largely conditional.
For instance a theist borrowing the image from another theistic group in an almost syncretic identification based on cross-cultural shared symbolism and meanings which aids the former’s religious worship, especially in conditions which are inhospitable to the worshiper’s religion or in one which they do not have access to traditional imagery I would not consider appropriation. We find this a lot in more recent history in regards to the use of saint and angel images but many diaspora religions and others, some of whom identify as pagans. This is plausible for those polytheists who follow religions that no longer have surviving intact example of their ancient icons in replica form or even original form to be inspired by if they possessed the skill to reproduce them. I do not find this as appropriation as it is the cross cultural identification and a loose syncretization in which shared symbolism makes sense and even maybe the motivating factor for it. For instance for myself I identify Leto in some regards with the dragon Delphyne, and she had a serpentine form as identified with Wadjet in Egypt. I find commonality for both her and Delphyne with the Asiatic Nagas. Therefore I have an image on its way (if it ever gets here!) of Naga Kanya as an appropriate icon of worship that I used based off this cross cultural identification. This is a case of what I would consider a theist identifying and making use of the icons of the cultural that they are identifying their own religious worship with.
The presence of icons of the gods as matter of art and décor I also don’t object to. They are kept mainly for the sake of their beauty and cherished in appreciation for themselves as they are. This has served to preserve many ancient images that may have otherwise been lost and demolished if there had been those who appreciated the asthetic quality of the images. I would consider this similar to numerous statues that hoisted publically both modernly and anciently which would have had meaning to some folks and been just admired by other folks. An attractive image can be kept and displayed for the sake of its attractiveness without being appropriation as no qualities are attached to it other than an asthetic appreciation for its form and often a sense of curiosity and appreciation for the native culture from which it came which I think can apply to many collectors of various replicas of ancient art. In fact those who collect images for aesthetic reasons tend to be very well informed about what the object is, what deity or spirit is represents, and even in many cases how it was used. Identification of deities in their statue form in modern times can often be due thanks to rather obsessive meticulous collectors and historians (ie professional collectors) lol.
What I would consider appropriation would be the use of a religious icon for that which it was not intended. That is to say an icon and can be ornamental and it can be used in cultural and cross cultural theistic worship, however when one takes a religious icon, designates all of its original symbolism as being without value and/or false but ritualizes the icon for an entirely different ceremonial/ritual purpose that neither recognized or honors its original meaning, I would consider as walking the fine line into appropriation. This is due a blatant ignorance and misuse of an important spiritual/religious symbol in a way that has nothing to do with its original intent, and often done so while deriding the beliefs regarding that image. This would be in a similar category of other religious and ceremonial things which have been taken from other cultures and completely misused in a way that is no way tied to what it was intended to be used for. This is a recognized rampant issue among those who appropriate native American symbolism and spiritual objects and re-designating them without any knowledge or education about said items. As such I can understand the objection to non-theistic use of theistic images for humanistic spirituality as appropriation, especially in cases where theistic spirituality is being derided and disrespected. Further it seems that there would be no reason for non theistic individuals to use theistic imagery and icons. By utterly dismissing and removing any theistic identity to the icon it is no less desecration and destruction towards the item than it would be physically removing it from the earth. It is damaging towards the history and education of the theistic spirituality from which it arose. Especially when there are many ways a non theistic spiritualist can express their spirituality without borrowing from theistic imagery in ways that theists, and especially polytheists regardless of the state of its native culture, consider blatantly disrespectful.
To put it this way from a theistic perspective, the image of the gods are more than just images but are representations of very real divine beings and spirits, to spiritually make use of it and destroying the theistic identity with the image can be considered a kind of subtle violence towards the gods and spirits we revere no less insulting that someone taking an image of the god and smashing it to bits. Does it harm the deity? No. Does it potentially damage or influence human-divine relationship via the use of that sacred image? Yes I would say so as one blog reminded of sacred symbolism that were appropriated and co-opted for foreign use to their original meaning and use and now have such negative connotations because of this that it has been abandoned by a number of folks such as the case with the swastika. This blog poster through this example provided a very good reason that we should object to the use of sacred theistic images for completely other and unrelated purposes (and while I understand the value of non theistic humanistic spirituality it is very different from theistic worship in the use of the icons as spiritual intermediaries no matter how the image is dressed up or how attractive it is made to look if it is not used for the purpose of worship then it is falls under the realm of other purpose).
Now on a personal note while I hate the concept of gods existing as archetypes, and have hated it ever since I was first introduced to it. A non theistic humanist collect images of the gods as part of this philosophy of archetypes (but which still is attached to the identity of the god) as décor and collectible art doesn’t bother me or cross into the realm of what I consider appropriation. I would only personally consider it such if it crossed into a non theistic spiritual use of those icons/statuary. Even then I can object all I want, but I can’t change what you are doing nor would I fool myself into thinking I had any input on what you do in your spiritual practice. All the same though, I would hope that said individual would not be surprised and understand the root of the objection rather than getting up in arms about it. It isn’t an attack on their non-theism or spirituality but about protecting and preserving the sacred in our own spirituality from the potential harm, pollution/miasma and any damage through causing harm to the divine link between gods and spirits via the representation with their worshipers. Thus we are going to take it personally as we take our relationship with the gods whom we revere and adore quite personally.