I decided to turn on the Battery Percent display on my iPhone 4 a few weeks ago. It’s off by default.
After I did this I notice what seemed to be irregular spacing/alignment on the numbers. It happens with most of number pairs.
I thought it was misalignment, but on closer inspection, the numbers are technically aligned horizontally. What seems to be happening (or not happening) is that rounded numbers are not dipping below the baseline as they should.
Characters in a typeface, when designed correctly, need to rise above the cap height and dip below the baseline in order to appear balanced when sharing a line with flat characters.
This is the problem with having a super high resolution display (326 dpi) like the iPhone 4 has – mistakes and much more obvious.
Get on it, Apple.