Seam, welcome to the forum.
Image avatars are coming in the next major update, version 3.5, which @AeonRob predicts will be released by the end of the year. It’s part of an enhancement in the visuals when showing related events and items. We’ll be able to choose color or grayscale short labels and use image avatars in labels and cards.
For consistency, items of types that use avatars will now always show their avatars instead of an icon. In my particular case, if I decide to use avatars, I’d probably only use them for characters, rather than, say, locations. So I’d set the “characters” item type to use images, but not the “location” item type. In testing in the beta, it works great!