The triptych player provides three players, side-by-side, which you can use to simultaneously view the same clip in different contexts. For example, you can set the middle player to play the clip, the left player to show the clip's incoming frame of the current element in the timeline, and the right player to show the clip's outgoing frame.
To compare three shots in the triptych player:
The clip appears in the triptych player in all three viewers. Coloured positioners help you identify clips in Triptych view (green, yellow, orange from left to right).