It's a bash script. Execute it and it shows a dancing woman.

Edit: ok the bash thing is a red herring. It works if you just "cat lady".

you are right, I started out with piping it into less, to see if you are right and damn it if you are not right. I thought he did something with delays in the output. How and why does this work?

ANSI escape sequences. Your terminal interprets them like move cursor to row x, column y. Set color green. Etc.

https://en.wikipedia.org/wiki/ANSI_escape_code

Interesting? but why does bash execute the code from standard output instead of simply displaying it to the user?

It's not bash. You can remove the shebang line and cat the file, and it still works. It's simply your terminal interpreting the ANSI codes and displaying the contents of the file.

well a shell command if you can excuse my nitpicking. Had it been a bash script he wouldn't only have made a really nice easter egg but also found a security hole in curl.