Last nights coverage coming from the box instead of the NY studio would have been awful. The box is way too clinical for a big event. The dull colours and the clinical nature of it would think you are going to a formal meeting rather than an important day in News, I'd have felt so disconnected.
Underneath the studio is a promo area for whatever is flavour of the month at Sky - VR, Boxsets, whatever else. At the moment it's the Sky Cinema Christmas campaign. So intended less for on screen, more that you see it on screen.
One thing that has slightly perplexed me in regards to the new studio is why they ended up replacing the glass on the desk with a different piece that contains a cut-out for the screens beneath - all throughout the pilots the glass was one entire piece, with the screens still underneath and obviously visible, but in time for launch it was swapped out with something that doesn't look so good. The BBC, ITV et al all manage with having the screens entirely beneath glass, so is there any reason Sky News couldn't here? I notice on YouTube there's a video of the set build of the Sky Sports News HQ studio, and whilst on screen today the glass again has a cutout for the screens, you can see in the video that originally it was one piece of glass with screens below, so this was also changed late on.