if you paste contents which contain a very particular string ("intends to sue the human race for stealing our honey"), the contents are replaced with the phrase "the bee movie script? really? how original"
Also got got. I assume the Bee Movie script is the first choice for a lot of people needing an ad-hoc big block of text. It also compresses pretty well.
It's mostly what heliodex said, that it's a copypasta when ppl need big text. There's also a compression meme around the bee and other movies (on yt: bee movie in 10s or it gets faster everytime X). But unlike i thought in the beginning it's not a zlib specific joke.
It's the resulting string the tool gives instead of the actual compressed string info. You can see the result directly by putting some text which contains "intends to sue the human race for stealing our honey" into the input text box.