It's unasked for comments about a young person's physicality who has never asked to be in the spotlight. It's not shaming deliberately but it's poking fun at him when he shouldn't really be a target.
Gary Barlow's son may find it very funny, but I can think of plenty that would be a bit hurt and want to just go about their business. As I say if was just about height that's one thing (still not ideal in principle) as he isn't a remarkable height, but the wording of all these memes isn't about him being tall. I think if it's a young person who has never asked to be famous, leave them out of personal jokes.