prince in disguise parallel # zillion
The dress Blair wears the first time she kisses Dan (4x17) is one of the dresses we see in the Paris shopping porn montage while Blair and Serena are shopping for her date with Prince Louis (4x01).
Rochellena from FanForum noticed this parallel: In 4.01 they do a montage of a bunch of Paris stores, one of the few times they actually focus on a dress for 2 seconds instead of just one is when they are showing the dress that Blair later wears in the first kiss scene. I thought it was kind of interesting with all the speculation about parallels and hints from the first episode.
Intentional, coincidence... IDK.