Kitsch is art that's garish, nostalgic, and very low-brow. Some people who love the aesthetics of souvenir culture think kitsch is really cool, while others think it's in very poor taste.
Kitsch is a German word that's been adopted into English, meaning "worthless, trashy art," or the quality of that art. A ceramic figurine of a puppy with sad eyes is pretty kitsch, as is a velvet Elvis painting. Of course some people think that kitsch is really beautiful and fill their homes with stuff that other people consider trashy souvenirs. If your painting teacher tells you your portraits are kitsch, that's probably not a compliment.