What is this car and is that a gas cap?

My wife took this photo in stopped traffic because fluffy doggo (total missed fur face Friday opportunity). But my first question is what the heck is with that giant gas cap/port in the body panel behind the door??

What is this vehicle? I see any grey CUV on the market. My wife’s assesment was “I dunno, think maybe it was a a Jeep”

Could it be a power/gas cap combo for a hybrid (seems I’ll advised), natural gas isn’t that big, There’s no hydrogen round here that I know of.

Help me Oppo you're my only hope.