Some of these are probably fingerprinting but the Twitch one isn't (I worked on the video system at Twitch for a number of years).
"player-core-variant-....js" is the Javascript video player and it uses WebGL as a way to guess what video format the browser can handle. A lot of the times mobile android devices will say "I can play video X, Y, Z" but when sent a bitstream of Y it fails to decode it. WebGL allows you to get a good indication of the supported hardware features which you can use to guess what the actual underlying hardware decoder is.
This is sadly the state of a lot of "lower end" mobile SoCs. They will pretend to do anything but in reality it just... doesn't.
"player-core-variant-....js" is the Javascript video player and it uses WebGL as a way to guess what video format the browser can handle. A lot of the times mobile android devices will say "I can play video X, Y, Z" but when sent a bitstream of Y it fails to decode it. WebGL allows you to get a good indication of the supported hardware features which you can use to guess what the actual underlying hardware decoder is.
This is sadly the state of a lot of "lower end" mobile SoCs. They will pretend to do anything but in reality it just... doesn't.