As for me, I think it is guest performer. Here is an example, 他是我们邀请的表演嘉宾！

Hallo, I’m here to take the question. 表演嘉宾 means performing guests, who is invited to the stage as a special guest. For an instance, you’re gonna have a party, and you’re gonna invite me to sing for it. So I'm goona be your 表演嘉宾。

Honored performer. It's a polite way of introducing the next performer.