The first two items you can pick up (While stuck in the stall) are
- the Toilet Roll (By unraveling all the toilet paper from the holder)
and
- The cellphone (On the ground near the concrete wall)
The last object you can pick up that would be relatively quick, is the hammers handle that's on the ledge (Next to the Toilet Paper) to the left immediately after leaving the bathroom stall.
Achievement unlocked!