I found this post by googling: https://themustangsource.com/forums/...-radio-494026/

It's the only reference to what's happening that I've found.

I had a strange stereo/environmental control occurrence and I finally found the right sequences to replicate it.

Does anyone know what the heck this is?

2014 Mustang - Sequence 1: 2014 Mustang - Sequence 2:
(I needed vertical video to get both sections at once. Don't kill me!)

 

Looks like a test mode to me.

 

I would think that except that fan icon that pulsates in the second one, it never shows up at all during normal operation. The only reason I know it's there at all are from the two screens. Same with the secondary temperature number.

 

Test mode / The fan and dual temp display is probably applicable to some other Ford model that uses the same screen, and has dual zone climate (like maybe a Flex or a high end F150)

 

We have a winner!