This same sort of approach has been used by terrorists in the past.

So?

You need to take ppi into account. The iPhone has more screen density.

The article said "8x as much screen space", not pixels

That's a good point, but there's only about a 25% difference between the two.

Maybe the basis is an iPhone 4 instead of an iPhone 5? I agree that an iPhone 5 would be more appropriate, as everyone designing for an iPhone has visuals for that.