Is this a crack in my iPhone? Evaluating my trade-in condition.

[digduggler]

Looking at selling either my wife's 4 or my 4s after getting a 5. The 4 is in flawless condition. My 4s I dropped this summer on concrete and got a large nick, which with amazon/gazelle I can't tell if it takes it out of 'good' territory to broken. If that's the case, there is no point getting less for a perfectly working 4s than a 4. I'm sure I'll get opinions all over the place, but this seemed like an appropriate crowd to get some ideas. I've lifted it out of the case and taken a photo - this is the only damage to the phone (and the only time I stupidly took it out of the case to see what that would be like. Which I kick myself for every day).