So I asked, and you can't do captures to use for the backgrounds with the headset (I'm guessing they use better equipment and maybe some processing), but it does do "spatial photos and video". That was part of the demo in the store and they're really impressive. The 15 pro can also capture a 3D video that still looks cool, but has noticeably less depth than the captures with the headset.

I'm not sure the exact technical details, but there are a whole bunch of cameras and other sensors. I'm assuming it uses all of them combined to capture the 3D photos. But there was a lot of depth in the version I saw in the demo.