Thank you for attempts to help. It looks like the matter is not with SSL , because dev server is not loading images into the pages either.
Hence, I cloned production --> to dev again, so they are identical, and I created users 'saguaros' and 'jatest' as they where prior
(passwords are set to the prior values). Hope this "refresh" from prod will help with further investigation as to why the images upload is not working. I think it is related to some kind of permissions. Please note, that a Registered user can not create a review for the other user page! Could this be related? I.e. the Create Review button is not simply shown when I press on stars to create a review. see the picture.
Or it is a different matter entirely? thank you!