Well, Celine's stage looks kinda like one for an opera theater. Plus, it doesn't have a catwalk so Britney probably would be limited to just the actual stage. I guess Britney's is more reminiscent of one you would expect at a concert for a pop star in an arena. That's kinda what it looks like. A mini-arena. Didn't look like a 4.5K venue from the pics I saw.
And Kylie's Aphrodite tour stage is great, but it's huge, could that look nice in a venue like Britney's?