Making fun of someone based on something as trivial as
how they hold a pencil is ridiculous and immature. It's something you might hear a kid say about a primary school classmate.
Anyone creating
and sharing such "memes" is making a fool of themselves.
There are good reasons to dislike someone, such as their significant use of private jets. Carbon emissions affect the planet, and therefore everyone.
There are really dumb reasons to dislike someone, such as their way of holding a writing instrument. Such a thing affects absolutely no one.
Basically, the image
attached here is making fun of Swift simply because she is different than whoever made the image, and the text makes it obvious it's meant to be ridicule rather than in good humour. It can even be seen as saying "different than you = bad and deserving of dislike", which as a way of thinking is the start of many vile things.