the basis for friendika looks solid. it might be a good idea to start collecting different 'use cases' in a wiki (like: posting an event with attaching a picture) to find the limitations quickier.
seems to work (with reloading the page) from the timeline. when answering inside the notebook view, the site loading stalls. i get the access denied if i open another friendika page afterwards.
it seems it posts, each time you upload a series of photos, a single one as a representative on the timeline. you can still see all pictures when you open the user's photo album.