Halo Waypoint Easter Egg Background Uses?

Everyone knows the easter egg when you press X at the main screen of the Xbox app Halo Waypoint, and the Halo:Reach credits and some backgrounds that are included, right? I was wondering what the backgrounds purpose and how to apply or use them in a way. If you know any info on this, please reply.

Hi, welcome to Waypoint.

Can you please elaborate what you are mentioning?

Account Settings

It is used to change the background for your Spartan Model on Waypoint Console App and Career Overview page.