The picture is from bobsag´s hosting facility, he therefore doesn´t own the majority of the shown miners.
It also looks like his thermal engineering isn´t optimised to the fullest extent, as there is a significant amount of unused space in those racks.
Hes already pulling a lot of density. Unless he can somehow duct out all of the hot air, im pretty sure hes capped to capacity due to not having a hot/cold isle containment.