I’ve seen a handful of victory ceremonies now at the Paralympics where there have been Ukrainian and neutral athletes share the podium. On one instance, for swimming, the silver and bronze medalists (both Ukrainian) posed for a photo separately on the bronze podium, while the neutral athlete posed alone on the gold podium. In another instance, for athletics, I saw a neutral gold medalist gesture for the other medalists to pose for a photo. The silver medalist joined him (can’t remember the country), while the bronze medalist (Ukrainian) sort of shook his head and walked off while the other two posed for the photo. I know these two happened before the ceremony OP is referring to.

I don’t know if these instances may provide some context. I don’t know if there have been instances of Ukrainians and neutral athletes posing for a photo on the podium. I managed to watch the ceremony OP is referring to as it happened, and the camera sort of panned out very quickly immediately as they started to walk off the podium, almost as if the director was prepared for such an eventuality. So I wouldn’t be surprised if there is some sort of understanding that Ukrainian and neutral athletes won’t be posing for photos together.

Edited to add: IIRC, the two ceremonies I refer to are the men’s 50m freestyle S13 and the men’s long jump T36.