[sirn]

As I've said below[1], less margin on the edge will make more room for app title for the 2nd and 3rd icons.

[1]: http://news.ycombinator.com/item?id=3171496

[pyrtsa]

Oh true, missed that. Finally pulled out the phone to realize this. And then the other option 16+20+20+20+16 / 32+40+40+40+32 already has too big a difference between the margins on the edges compared to the ones between the icons. Makes perfect sense now.