The Paul Varjak Effect refers to the character Paul Varjak from the movie Breakfast at Tiffany's (1961) played by George Peppard, and the way he goes from being absolutely dreadful to being absolutely gorgeous throughout the movie.
this is then used to referring to similar men; going from ugly to not ugly or not likeable to likeable. this term can apply to any men, and men only.
examples can also be: "george is such a paul varjak!" or "fred is paul varjak-ing it!"
"that man was so ugly in the beginning, but now i quite like him. he's working the paul varjak effect"
"oh i see what's going on here! it's the paul varjak effect!"