Hi,
"What does this mod do?"
The hack allows everybody to see the pictures they uploaded themselves, but only those people in a specific usergroup (for instance paying members) to see all pictures.
"Did you already get an answer at photopostdev?"
Must admit I did not post there as I figured this would be more UBBT related than PhotoPost. The post in question was more than 6 months old as well.
Did have a bit of play with it myself, but could not get it working.
Sanuk!