Availability of tickets.
Well there's still standing tix available (never a good sign).
A couple of those blocks are misleading as there's only a couple of tix available for resale in them. I suspect other blocks are not being sold at all (it's unlikely corner seats have sold out before some of the other blocks)
However there's also blocks which are maybe half sold.
Looks like there's probably a load of corporate seating that's been sold from the look of the plan.
At most the venue is about 50% capacity.