Liking pictures considered cheating?

If your boyfriend likes girls pictures who are way prettier than you on Instagram or Facebook.. or wherever. Would you be upset?

My boyfriend always likes the same girl’s pictures and she isn’t following him back but he’s following her (Instagram) it’s just ALWAYS her pictures and it just gives me this weird gut sink.

Please don’t be rude. I’m already trying not to have a panic attack about this or handle it the wrong way/bring it up to him. I don’t want to cause any problems with him.