Just an FYI some tips below from Major Nelson....I might dabble with this if I have time its cool they are doing it, I'm sure we will start seeing some funny ones emerge:
Creating a custom gamer pic for Xbox One? Be sure the image is at least 1080x1080 and JPG or PNG format. Have fun!
Also, if you have the One Drive app installed, you can put your gamer pics there and browse to it from the console to choose it
I didn't find the right solution from the internet.
- Digital Campaign Video Examples