Can we please get rid of this idea that an iPhone is optimized and other phones are not. This may be the case but I assure you that is not what the benchmarks are showing.
If I need to make myself any more clear why the iPhone beats the old Androids in that benchmark: its that an iPhone 4S has a Series5XT MP2 GPU and those other phones just have a Series 5. Its a dualcore GPU vs a single core older GPU. This is also the reason the Galaxy tab beat the iPhone 4S, because it has a ULP Geforce GPU and a faster CPU.

As jalyst said, benchmarks do not really show you much about OS optimisation.