In "The Dead" by James Joyce, what is the significance of Gabriel seeing himself in the mirror?
Here are the passages that describe the moment that Gabriel sees himself in the mirror (they don't have page numbers because they're taken from eNotes' excellent online version of the text):
As he passed in the way of the cheval-glass [Gabriel] caught sight of himself in full length, his broad, well-filled shirt-front, the face whose expression always puzzled him when he saw it in a mirror, and his glimmering gilt-rimmed eyeglasses.
Later, Gabriel muses on this experience in a fairly negative way:
[Gabriel] saw himself as a ludicrous figure, acting as a pennyboy for his aunts, a nervous, well-meaning sentimentalist, orating to vulgarians and idealising his own clownish lusts, the pitiable fatuous fellow he had caught a glimpse of in the mirror.
All of this happens around the time Gretta, Gabriel's wife, tells him about Michael Furey, the young man she loved in her youth in Galway. The story is a romantic one, and Gabriel quickly realizes that he is not his wife's true love after all and that he has never captured her affection the same way this young man did. Within this context, Gabriel's bitter evaluation of his reflection becomes very important. Gabriel's reflection in the mirror becomes a physical manifestation of his realization that he is not as important as he seems. Indeed, the reflection underlines Gabriel's sudden recognition of his own ridiculousness and relative insignificance. In that case, Gabriel's sight of himself in the mirror becomes a pivotal turning point in the text, as it is the beginning of the epiphany that ultimately destroys Gabriel's illusions about himself and forces him to reassess some of the most significant aspects of his life.