As someone that never saw the movie. All the clips, gifs and memes people make about it are the Ken scenes. Nobody talks about barbie presumably because her character and performance were good, but just kinda safe, middle of the road stuff.
I saw a few memes from her but her acting wasn't middle of the road by any means. She had to do the more dramatic parts and Ryan did almost all the comedy. And we all know comedy does give more material for memeing.
Also I noticed her memes were showing in my wife's feed so I assume there's some echo chamber effect going on.