This entity tells the game where the spectators will spawn, and where the screen will point when a match is finished and the score table (in Skirmish/multiplayer games) or podium (Single-player games) is shown.
Any map should include it. The mapper only needs to place the info_player_intermission entity. It should be linked to an info_notnull or to a target_position entity. Alternatively, it may just have a "facing angle", set using "angle/number" key/value or "angles/pitch, yaw, roll numbers" key/value.
The Levelshot can be taken with the "levelshot" console command, so it's a good idea to bind it to some key. Just press the bound key in-game to take a levelshot from the info_player_intermission point and save it in the <homepath>/.openarena/baseoa/levelshots folder. It's saved as a 128x128 TGA image.
If an info_player_intermission isn't found, the game fallbacks to either an info_player_deathmatch or info_player_start.
The levelshots in PK3 files are stored in the levelshots folder.