My Mavic just arrived. I did the firmware update, and all I see is this for the video feed. I'm freaking out, what's going on? I'm using iPhone 7 Plus
Do I have a defective unit?

Remove the SD card and see if it still behaves the same.

Reinstall the app and try again.

https://forum.dji.com/thread-76913-1-1.html

Flybee Posted at 2017-3-29 12:39
Reinstall the app and try again.

https://forum.dji.com/thread-76913-1-1.html

Yes
I would try to install FW again then try

Another thing to check would be the cable -- use your iPhone's Lightening cable and see if that works.

Asainz320 Posted at 2017-3-29 11:04
Remove the SD card and see if it still behaves the same.

I second this as if you have a corrupt or incorrectly inserted SD card you get a similar display and also try using the port in the middle of the controller with your own cable.

Are you filming a golf course?? If so it doesn't look to bad?

Did you enable the hardware decoding from DJI GO app?