Frankly, Bronx exhibit was rather disappointing for me. Sorry, Zooplantman. Some cages, high, against the light, and making it difficult to view animals. And generally dark - under trees and with hole-like structure.
Rather better was small exhibit of red pandas, making it impossible to see where it ends.
Best snow leopard enclosures I know are Zurich and Basel. Both are open-roofed, both have partially widely spaced fence (deer fence in Basel and chord wire in Zurich) and partially unrestricted view (ground raises). Both have sun, rich vegetation of grass and bushes and sloping backdrop providing cats good lookout area. In both, I saw snow leopard each and every time I visited these zoos.
Little can be improved over there. Maybe make some gigantic exhibit, if you have a natural canyon in a zoo, and put snow leopard next to goats and other C Asian species.
Well, one thing which could actually be changed is native Himalayan vegetation. Basel has dwarf pine, which for every European is symbol of high Alps, but doesn't occcur in C Asia. And Himalayas have lots of fantastic rhododendron and alpine flower sp.
In Basel, cats have enrichment from neighboring tahr exhibit. I saw cats sitting by the fence, watching and licking lips. Tahr, in turn, grazed two meters away in full view and absolutely ignored cats.
Zurich has too narrow public paths and too small viewing area, prone to fat families blocking view. Probably from general lack of space.
Zurich is better. Cats blend with color of rocky ground on the slope of their exhibit. I guess thats why wild snow leopards roll in dust before stalking prey.