As Tracy throws her socks into her trashcan, and then her teddies (both from the bed and from the wall,) in nearly every shot the teddies differ positions/return/disappear etc.
Mentioned on Commentary - the poster at the bus stop "Beauty is Truth" is a picture of Nikki Reed's (Evie) eyes on another woman's face. The picture is supposedly symbolic because each time we see the poster it is more graffitied/ruined, symbolising how Evie is making Tracy more out-of-control and dirty (e.g. introducing her to drugs and sex.).