'appear upset' is correct and usable in written English.
You can use it to describe a person's expression or behavior in a certain situation. For example, "The man appeared upset when he heard the news."
Mr. Stone did not appear upset.
But participants said the members of Congress did not appear upset by the delay.
Replays showed Wallace may have slightly lowered his shoulder, although no whistle was blown and Robinson did not appear upset.
David Lytel, the founder of the Committee to Redefeat the President, did not appear upset with the turnout.
Bakkila didn't appear upset by the uproar, even when it seemed as if every social-media blog and Internet forum were raging at him.
In a conversation recorded March 23 between Tokhtakhounov in Italy and Anissina calling from France, both appear upset by the F.B.I. investigation.
She appeared upset and left the restaurant in tears.
Approached Tuesday, neither player appeared upset that he would be playing with Woods.
But Barak aides said Labor had voted solidly for Mr. Peres, and Mr. Barak himself appeared upset.
But he appeared upset when Alfonzo was ruled safe, which replays verified.
It was not clear why; Colonel Pohl appeared upset and said no classified information had been discussed.
