Just before he was killed, Stephen saw the Son of Man doing what at God's right hand?

Answer: Standing

Stephen said, "Look, I see heaven open and the Son of Man standing at the right hand of God."

“But Stephen, full of the Holy Spirit, looked intently into heaven and saw the glory of God and Jesus standing at the right hand of God. “Look,” he said, “I see heaven open and the Son of Man standing at the right hand of God.””— Acts 7:55-56 (BSB)