New Angle

Isn't it funny how an everyday object seen from a new angle can trick the eye? I took this, obviously, yet I had to really think about what it was when I first looked at the image. Can you figure it out?

Thanks for all the stars on yesterday's blip of Trainer. I'm delighted to report that he left the shelter for his new home very soon after I posted. He is now the new best friend to a retired, single, gentleman :)