You can program actions at each waypoint.
This is copied from the Litchi user manual that you can find on their website.
Waypoint Actions
Actions are performed when the aircraft arrives at the waypoint. There are six different waypoint actions, three of which accept an additional parameter.
You can add up to 15 different actions for each waypoint. Waypoint actions can be repeated by increasing the "Repeat" number. Setting repeat to 1 (default) means that all actions will be done once.
IMPORTANT Waypoint actions are ignored when the mission "Path Mode" is "Curved Turns" as the aircraft will not stop at waypoints then.
Stay for: The time in seconds that the aircraft should pause at the waypoint.
Take Photo: The camera will take one picture. For this action to work, recording must of off.
Start Recording: The camera will start recording.
Stop Recording: The camera will stop recording.
Rotate Aircraft: The aircraft will rotate to the specified angle. The parameter is the angle relative to North that the aircraft should rotate to (0° is North, 90° is East). For example, setting it to 270° means that the aircraft will rotate to point towards West. If the aircraft is already pointing West before starting this action, it will not rotate at all.
Tilt Camera: The gimbal will move to the specified angle (tilt). The valid value range is +30° above horizon to - 90° (look down).