Picture Perfect is a romantic comedy movie from 1997 directed by Glenn Gordon Caron.
Jennifer Aniston plays Kate Mosley: She is a single, very ambitious girl working at Mercer, an advertising company, but her boss tells here that she stands no chance on promotion because she is in no way tied to the company. Her friend/colleague makes up a story about Kate being engaged to Nick, a guy whom she just met at a friends' wedding. Kate doens't try to deny it, and it seems to work out. But then things get complicated ... Nick really loves her!
This movie reminds me of Bridget Jones's Diary where the main character Bridget Jones also thinks she loves a colleague (in this case her boss Daniel Cleaver), and then suddenly realises that the person she really loves, is Mark Darcy whom she had tried to ignore.