Both new iPhones look the same as before" is the most common complaint when it comes to the’s’ variants. Ever since the iPhone 3GS released in 2009, Apple has followed the’tick-tock’ strategy — the tick is the all-new model and the’tock’ has mostly internal upgrades.
However, with these new phones — they’re not exactly the same dimensions as before, even though they look identical. There’s a minor difference in thickness(6.9mm for iPhone 6 and 7.1mm for 6s - and 7.1mm to 7.3mm for the plus version