Australis said: I think it depends on how you are captioning it. There are a few combinations of key words (e.g. "Photo courtesy of") that trigger the vendor filtering, so they don't show up.
dave said: It's true that vendor photos don't show up there, and also I believe it limits that list to a certain number of genera. So if you post photos of daylilies, it'll show 2 or 3 daylily photos and then won't show any more in order to make room for other kinds of plants.