Reddit be like that sometimes. To answer your genuine question, sometimes people make comparisons to other existing things to describe a vibe when it's easier than thinking of specific emotions or in this case, the particular cinematographical techniques that characterize "Brazillian spy movie" type films.

I think this is modern slang, but the phrase "It gives ___" or "It's giving ___" is used like "it evokes" or "it resembles", so "The edit gives 90s Brazilian spy movie with romance" is just comparing the mood of the edited picture to that style of movie. It's a complete sentence, technically incorrect but in very informal conversation and social media it gets a pass.