I inspected this shower enclosure and this what I observed. It did not look like a mold issue and there wasnt an odor or evidence of cover up.
I would like some Nachi feedback.
http://i187.photobucket.com/albums/x296/dawlita/A%20Pictures/Home%20Inspection/Pic139.jpg
http://i187.photobucket.com/albums/x296/dawlita/A%20Pictures/Home%20Inspection/Pic140.jpg
From the pics it looks like the wall board was not properly installed and is not water resistant (green board). Any board will be eventually be damaged by moisture if not installed flush with the top of the tub surround, painted, and sealed with caulking at the edges.
Could you shrink the pic down a hair?
they may not be using the vent fan. alot of humidity is taken out using them. i understand there are timers that can be placed on them so once your done in the bathroom you can still let them run.
looks more like a bad install.
looks like mold to me. the only way to be sure is to test it. Take a swab sample. A very comon problum in the shower area, moisture + humidity = mold