Series 5 Watch, Red line on the top

Hi!

I bought myself an apple watch series 5 at an Apple Store 4 days ago and I've noticed this strange line going across the top prt of the display. It's only visable in dim conditions when a light is shined upon it. For example when laying in bed and having my night stand lamp turned on.. Is this normal? Or is it defected..? I have AppleCare+ but I suppose this would fall under the normal Warranty.

Grateful for any assistance

cheers