This screenshot from an AT&T commercial advertising the Blackberry Torch clearly shows that the subway station is labeled Gallery Pl-Chinatown Station-DC.
Only the subway station shown clearly is not the Gallery Place station.
Did AT&T just throw that in there so locals would talk about it? Well, it's a national commercial and even the youtube link shows it as Gallery Place - so they aren't changing it city by city.
It clearly wasn't filmed in the Gallery Place station. Or made to look like it.
So who knows why they labeled it that station? They do have a very large store that sits atop that station.