Canon EOS REBEL T2I Instruction Manual page 80

image Playback
This chapter explains features related to viewing photos
and movies, going into more detail than in Chapter 2
"Basic Shooting and Image Playback" which explained
the playback procedure. Here you will find explanations
about how to playback and erase photos and movies
with the camera and viewing them on a TV set.
About images taken with another camera:
The camera might not be able to propedy display images captured
with a different camera or edited with a computer or whose file name
was changed,