It can do well in places like China and India. Although the Chinese went gaga for the iPhone 6/6S not all of them can afford those prices. I think the SE is a way for those people to get a piece of the iPhone action at a lower price. There will be many in India who also can afford the SE but not necessarily the 6s. Of course many African countries will still be priced out and will have to stick to the bargain basement android phones.I don't think the iPhone SE was designed for emerging markets. Yes... it's the cheapest "new" iPhone ever released... but it's still $400.
There are Android smartphones that sell for $100 in emerging markets.
The iPhone SE simply replaced the $450 iPhone 5S while coming in at $50 cheaper. That's great... but it's far from a "budget" world phone.
The average selling price for Android phones worldwide is $215
iPhone is $691
So again... I don't think Apple is targeting emerging markets... even with the cheaper iPhone SE.