Gabriel is recognized as the angel who announced the birth of the Theotokos to her parents Joachim and Anna and who came to Joseph the Betrothed in a dream, telling him that Mary’s pregnancy was indeed miraculous and that he should protect and care for her. He then appeared to the shepherds near Bethlehem, telling them of the Nativity. Thus he was the key figure in revealing to humanity the Incarnation of Jesus Christ.
Gabriel was present during the Passion and Resurrection of Jesus. He is identified as the mysterious “young man, wearing nothing but a linen garment … following Jesus” who fled naked after he was seized during Christ’s arrest in Gethsemene. Most importantly, it was Gabriel who announced Christ’s Resurrection to the Myrrh-bearing Women outside the tomb.
Angels are incorporeal beings, though they nevertheless take on human form when appearing to mankind, it can be difficult to differentiate one from another in icons.
However, Gabriel is usually portrayed with certain distinguishing characteristics. He typically wears blue or white garments; he holds either a lily (representing the Theotokos), a trumpet, a shining lantern, a branch from Paradise presented to him by the Theotokos, or a spear in his right hand and often a mirror—made of jasper and with a Χ (the first letter of Christ (Χριστος) in Greek)—in his left hand.
He is the Angel of Dreams and Communication.