Hi @schlump,
I checked that the type of document property does not include the image type. Perhaps this is the reason the image column is not added to the document properties.
If the answer is helpful, please click "Accept Answer" and kindly upvote it. If you have extra questions about this answer, please click "Comment".
Note: Please follow the steps in our documentation to enable e-mail notifications if you want to receive the related email notification for this thread.