How do you work this thing????

Great now is my chance to finally take a bath in mommy and daddy's tub.....now I am not sure how this works sooo let me see.... do I stand back here or......... Wait I think you have to fool with these things.....
Now this is where the water goes...i think????
Oh man I think i here daddy coming......................
He is in the bathroom and he does not even know I am hiding shhhhhhhhhhh
OK the coast is clear..............now I think I will just sit here and relax till the water comes on....