Thats the clear case, it gets difficult with stuff like Star Wars memes. Disney probably doesn't mind someone using Darth Vader to tell a joke, they probably don't care if you stole the image and uploaded it as your own either, and they probably don't care if your joke is distributed on reddit either or whether they make money from it. Because at the end of the day, thet's sort of a free commercial.
Under the law though, you have to ask permission.
It's annoying to be honest. I give a lot of presentations, and not having every image on the internet available to me, is just annoying. But I work for a municipality, and it can potentially be held accountable if I use proprietary images without having permission to do so.
It's been like that for a long while by the way, but internet companies like Reddit have somehow gotten away with doing what the rest of us cannot. In fact they've build a big part of their business model around it, and now the EU is telling them they aren't above the law, so of course they're unhappy.