It says right on the transformer something like 'do not block 1m around transformer'. It's on an easment, which means the utility owner (enmax) can do whatever it pleases on that section of your yard. You're not supposed to put any 'permanent structure' over an easment either, enmax can come and tear it down and send you the bill for it.
I'm not saying don't do anything to hide it, but you are supposed to leave unobstructed access to the thing at all times. But hey, they can't fine you if they never find out I guess...
Michael Scott: "Do I want to be feared or loved? Um... easy, both. I want people to be afraid of how much they love me."