The Function sub-menu

Zebra's color is chosen at random
WZebra's color is chosen randomly (and, therefore who makes the first move) when a new game is initiated.

Zebra plays black
WZebra is black when playing. Black makes the first move.

Zebra plays white
WZebra is white when playing. White makes the second move after black.

Zebra observes
WZebra analyzes the positions on the board but does not make any moves. This is one of several ways to let WZebra analyze a game.

Zebra unactive
WZebra is asleep, presumably counting sheep (or gazelles). This is useful when WZebra's board is used for a game between two humans.

Spy on replay
When this toggle is set, WZebra will analyze all positions when a game is being replayed through the Replay game feature in the Game menu.