The S7 — as with the iPhone 6s — kept, mostly, the same look as its predecessor. Both feature metal bodies with glass screens. You get twice as many color options with the iPhone, however. One thing Samsung did manage to do though is reduce the size of the camera bump on the S7.
Samsung also was able to make the S7 IP68 dust and water proof—something the iPhone 6s is not. You can actually submerge the S7 for up to 20 minutes and it will work just fine when you take it out. The iPhone 6s isn’t waterproof, but it’s rumored the iPhone 7 could be—and it may even go further: allowing you to use the phone’s display with wet fingers.
As for size and weight the iPhone is still the thinner and lighter phone coming in at 7.1mm thin versus the S7’s 7.9mm thickness and 143 vs 152 grams