Apple TV Will Mirror Sound but Not Video from AT&T Uverse App

I recently purchased a flat screen tv and a Apple TV to stream Netflix into my office where I don't have a cable hookup. I also use the AT&T Uverse App on my ipad and iphone to watch television when I'm on the road or my roomate has control of the main living room tv. I thought I would be able to stream from the Uverse app on the phone or iPad3 to my Apple TV, but it only seems like I can get audio for some reason? The picture stays on the menu page on the television, and a grey note icon (like when you don't have an albumn cover in itunes) shows in the lower corner.

Is the app not compatable? Is there a problem with my apple TV? If it's "mirroring" my iphone or ipad, why won't it just show?

Iphone: Iphone 4, and I tried with roomate's iphone 4s

Apple TV2 (purchased 12/19/12)

Connected via HDMI Cable

Thanks for any help!