juxtopose:

Now I would not put an image such as the one on the left over my fireplace (if I had one) but I love the juxtaposition of the sweet flowery wallpaper and the smiling lady flipping off the viewer. A little bit of sass goes a long way.

juxtaposition (plural juxtapositions)
a placing or being placed in nearness or contiguity, or side by side, often done in order to compare/contrast the two, to show similarities or differences
(art, literature) two or more contrasting sounds, registers, styles etc. placed together for stylistic effect
(logic) a logical fallacy on the part of the observer, where two items placed next to each other imply a correlation, when none is actually claimed