To bump this - the no show of images with a CSV also affects entity lists. So they can't show images against selects when you also use big-image
Currently the only workround is to query the entity list into the form and spill it to the internal choice list, which then needs definition updates when the entity list changes.
Either way the list of media need to be in the form to force their upload, so the above is also required anyway at the moment.
I couldn't find a Collect issue that seemed related to it, but also not sure if it's a Collect issue or pyxform etc. (Enketo can't show the images either and has other non ideal behaviour with selects with images and choice filters.)