Strange headline for an animal without a brain. It does have a central nervous system, and responds to light from the eyes on the end of each of its arms — numbering anywhere from 5 to 40.
So you first parsed the sentence as saying 1) there's a well in the deep ocean 2) the well is pretty and 3) starfish can see it.
That makes grammatical sense but not, I think, any other kind.
It also makes sense if you watch SpongeBob SquarePants.
There's quite a lot happening in Bikini Bottom. For example you can see a "pretty pineapple" down there. And I haven't watched enough episodes to be sure, but doubtlessly someone has fallen down a well.
