In Ashley's apartment prior to and at the party, the black dress that Ashley is wearing has a shoulder strap over her right shoulder. When she returns from the party, the strap remains on her right shoulder until she sits down. The strap then changes location to her left shoulder when the camera angle changes.
The letter from the mortgage company shows 2245 Westley St. as the address of Carrie's house, that Anna lives in, but in the quick scene near the end in which Anna is arrested and being led away from the house, the address is different: 252 or 202 - only three digits.