With a little time to pursue this idea, I first upgraded to WithKnown 1.2.2 and then experimented with various API calls. I was able to create a Photo post, which included the description. But no image. At a loss, now, because the image from Bibliogram is definitely available and my RSS reader can see it. So I wonder why WithKnown cannot. Or maybe it can, but then fails to insert the image into the post. Also, apologies for spamming the micro.blog timeline.