One of the defining characteristics of angels is that they are messengers from God.
In the Icon ofSaint John, we see that John was more than a prophet. He was God's own messenger. Through John's proclaimation of repentance, the foundation of this message was made known. John brought the Good News that the Kingdom of God was near.
To represent this role of messenger, the icon shows John with angelic wings.
In his heavenly form we see John restored to wholeness. As a reminder of his martyrdom, John holds in a bowl his severed head.