What I now consider to be one of my favorite portrait shots, "Look" was actually captured on my phone on the set of a commercial I was filming.
Between setups, I wanted to see how the light looked from more "downstage", or shadow side, as I would have wanted to shoot it for myself. In the background, there's even lighting gear from the commercial.
The results speak for themselves and it was a magical moment that taught me as a cinematographer to always look at something how I would want to see it, even if I couldn't shoot it that way for a client.