Canon EOS-1D X Mark II DSLR Camera (Body Only) - Manual (Page 366)

Q Quick Control for Playback
366
To rotate an image, set [ 5 1: Auto rotate ] to [ On z D ]. If [ 5 1: Auto rotate ]
is set to [ On D ] or [ Off ], the [ b Rotate image ] setting will be recorded to
the image, but the camera will not rotate the image for display.
Pressing the < Q > button during the index display will switch to the
single-image display and the Quick Control screen will appear. Pressing
the <
Q > button again will return to the index display.
For images taken with another camera, the options you can select may
be restricted.