On day 29 at 19:49 minute mark, @cmuratori says, that because the patblt happens before the stretchDIBits if the page-flip happens in between the two calls we will see a flicker.
I don't get what page-flip means here. I can only assume he means repainting of the frame. But, isn't the Win32DisplayBufferInWindow function called on every frame? If so then how can a page-flip happen while that function is still running?
The timestamp in the video when he gave the explanation: https://youtu.be/EwhVulgF16g?list=PLnuhp3Xd9PYTt6svyQPyRO_AAuMWGxPzU&t=1163