Slightly off-topic: if you want to know how this works with USB Keyboards, check out this fantastic video by Ben Eater: https://youtu.be/wdgULBpRoXk

I don't know if everyone here is just a galaxy brain or what, but I'm surprised nobody has asked or explained the joke. The red bird is a CPU running lines of assembly instructions and the crow is user input causing an interrupt to press the e key. This particular type of interrupt exists because it would feel really bad if you were typing, and the text didn't show up until several seconds later when the CPU felt like processing the (hopefully) buffered input.

Quality meme op