Yeah, believe me, it's extremely "traditional" in China.
I've seen those pictures from 1990. I'm not sure what it's like before. But, considering I'm a Mainland Chinese and you ware watching a Taiwan movie. I think at least it have been like that since 1940. I believe that's because Chinese wedding ceremony, unlike west one, are mostly holding at a restaurant. There could have several couples have their ceremony at the same night. And there will have so many guest. Not all of them know will about new couple. Plus, bride always have amazing make up. So, without those pictures, it will be embarrassing if somebody goes to the wrong place. Typically, you'll see name in the poster. (yeah, we call it "poster". I keep my wedding poster in my cabinet)
We have picture in funeral as well, but it's different. It has to be "black-and-white photo". So if you transfer somebody's picture (mostly formal one, front face, good looking) into "black-and-white", you should take care of yourself. That's really a curse. Your Chinese friend will feel insulted even you know nothing of it.