The profile picture thing is pretty much the same as what Facebook does. For users that have Smithereen-style profile pictures, it becomes clickable in the profile. Clicking it opens the album and lets you flip through older profile pictures of that person.

Tags need approval because there's also a "photos of me" pseudo-album where all photos where this person is tagged live. There are new privacy settings for who can tag you and who sees your tagged photos (it doesn't affect the newsfeed tho).