Hi there kimberlie17,
Thanks for using the Apple Support Communities. I understand you’re seeing an unexpected issue with your new iPhone XR display. I understand how that could cause some concern and I’ll be happy to help with this.
First, I would remove any case or screen protector you may have on your iPhone and see if that helps. If not, try restarting your iPhone and see if the bright remains throughout the entire process. If it does, your iPhone will likely need to be looked at by an authorized technician, and you’ll want to reach out to Apple Support using the following link. They can provide you further support on this:
Contact Apple Support
Best wishes.