David Fincher Double Feature What Was He Thinking?

So I just got an e-mail from the Walter Reade theater at Lincoln Center touting the David Fincher mini-film festival pairing his films in double features with classic films chosen by Fincher. Pairing Zodiac with Chinatown certainly makes sense to me as does pairing Fight Club with Butch Cassidy and the Sundance Kid but I can not for the life of me figure this one out - http://www.filmlinc.com/wrt/onsale/fincher/se7en.html. Is it just because you need the unabashed happiness to recover from Se7en? Does anyone out there know the answer to this? If anyone goes to the interview with Fincher and finds out the actual answer please let me know.