Source: https://www.youtube.com/watch?v=icLNtF_ehwo
When I sat in the exit row of a plane from Sacramento to Denver. I saw what looked like a glitch in the matrix. A weird spike in the fabric of reality! Turns out it was refraction, the high-pressure shockwave over the wing was acting as a lens and distorting a bit of the image, as well as projecting sunlight in a streak on the wing.
They got quite interesting at times, sometimes with multiple refraction spikes
(The second leg was from Denver to New York)