Comment on what others have said, do you all expect others to reply?

Sometimes I really don't expect to comment on what others say, just express my own sigh and don't want the other person to come back to you. Sometimes when the other person answers you, you may have nothing to say, but it will be embarrassing. For example, today, when I saw a girl in a circle of friends and sent a photo of myself standing upside down, I let out a sigh, as if you were amazing. Don't expect the other party to reply anything.