The P4 camera does not zoom. If you're using an Apple device, you can pinch the screen to zoom in up to 2x digitally.
P4 camera does zoom 2X with iOS (pinch and spread on the screen, while recording 1080) and I also think it is now supported with Android. The P4P camera does not zoom with iOS or Android, but the Mavic does with iOS, and I think Android too. I've asked @bladestrike about this zoom shortcoming to the 1" sensor in the P4P, if DJI is working on it, but no feedback yet.The P4 camera does not zoom. If you're using an Apple device, you can pinch the screen to zoom in up to 2x digitally.