Self-portraits by artists could be considered the longest, and oldest, way to take a selfie.
Elizabeth Vigee Le Brun did several self-portraits, and when I see simple reproductions of them, I'm impressed. If I'm standing in front of one of her portraits, I feel that I can see what a gentle person she was (I hope), and I'm fascinated.
When I viewed reproductions of Rembrandt's self-portraits, I wondered what he was thinking to paint so many pictures of himself. After seeing an original, I changed my mind. I was in awe, just as I am with Le Brun's work.
Norman Rockwell even did artwork of himself painting a picture of a picture of Rockwell.
John Singer Sargent created a self portrait, but when viewed beside the likeness he did of his teacher, Emile Carolus-Duran, Emile's visage seemed to have more depth. As a student, you do want to impress the instructor, and I'm sure Sargent did.
We would have no idea what many of the artists of the past looked like if it not for their selfies, and I'm happy they took the time to create them.
BTW: That's a selfie of my hand holding a paintbrush.