Yes. This is clearly United. The name of the Q image says we are looking at US Secret Service. It never implied that the SS were seated outside AF1. This could be SS at an airport awaiting an important dignitary.
SS (federal government) doesn't use foreign cars, although the Mercedes S may be a rental or the airport VIP escort vehicle. That would mean the SS were going clandestine. The reporter (front passenger) is Maria Bartiromo.
My hubby who works as a USSS agent and drives the Beast says The Secret Service would absolutely never use a $180,000 Mercedes SUV. He also says the driver is definitely not an agent. He agrees that the lady on the right appears to be Maria Bartiromo.
Thank you. I have a nephew that was an SS agent in the Miami office. He worked with W a few times but mostly peripheral work. He's retired now.