Fascinating. That’s much more than I expected. Thanks for taking the time.

The image doesn’t look like a photo. The meme is about porn. Digital images can contain large areas of repeating patterns (uniform color areas for example) that can be compressed losslessly pretty well. Even slight noise from an image sensor can block that kind of compression.

You’re right. png can be lossy but that’s uncommon in the wild.

bmp should not compress more than other media files. jpeg, png, etc. can compress so much because they are lossy

Python doesn’t have to. Windows supports both out of the box. Has been for many, many years