The stalk the bloom is on is only about six inches tall - there are a couple of taller ones. I thought this might be why it's called "hidden", but apparently mine is just a fluke. Billy says they bloom at the top of the tall stalks like everything else.
It's been a couple of months since it bloomed and it hasn't bloomed again - down low or higher - probably due to the amount of shade. I've thought about moving it and our other tropicals to a sunnier spot, but I like them by the pond.