Photo Quality Airplay and AppleTV 2

Hi and thanks for reading,

I just bought a 50'' Full HD TV and made some test with my Apple TV 2.

I noticed that by Air Playing my iPhone photoes I have not the same definition and quality that I have by uploading my photos from my iPhone to the TV buildin photo viewer, which on the contrary makes them looking great.

Is this due to the fact that with AppleTV 2 photoes aswell are mirrored in 720p instead of 1080p?

Can I expect to fix the issue by upgrading to an AppleTV 3 @ 1080p?

Many tnxs