at this time anyway... they have yet to fix a few bugs, people may have noticed-
Thumbnails of NSFW and private photos show up and are visible to those who don't have access to them. (I.e. - not e.g., please... - if you aren't on the friendslist, or have "can see NSFW" turned off, then you can still see the photo if you are viewing the photo just before or after it in the sequence. (People who aren't logged in aren't, I think, able to view inside galleries, so I didn't include that as an option.)
Navigation goes through rather than over and around private photos- again, it should avoid photos you can't access (coding that I'm so used to LJ, say, having perfected for sequences of journal entries with much more complex levels of filters than we have here, that I'm surprised to bump into the problem here- but it may not be so easy to program after all...)
Nothing anyone here doesn't know about, but I thought I would put some of it down in one place before I went back to, e.g., music-stuffs (decided not to "LilyPondify" the Kopylov quartet, going to work on a modern score instead and instead of displaying it here, send the result to someone I know who knew the composer, for his opinion), cleaning room, laundry, ... etc.!!... eep.
Anyhow:
suggestion: put all your NSFW photos in the same folders, away from others.