Because someone submitted it and people upvoted it? Getting enough upvotes to stick on the front page for a bit is a good yardstick for relevance, I think.
(Not the one who downmodded you, just piping in)
What's wrong with "just using ImageMagic"?
A simple comandline wrapper of ImageMagic isn't really news. But if enought people like it, it's ok. No news for me
You are not getting it. The point is it randomly generates image manipulations with several steps (= filter).