Even if you managed to get it working it could be (and probably is) iCloud locked. It's a good way to hide that.
I saw an iPhone with non working screen but still under warranty and no visible damage. Checked the warranty with Apple, they said it was valid. Sweet, sounds like I should be able to get it replaces for free right? No because checking the IMEI revealed it was stolen, meaning no Canadian carrier would activate it for me and it was very very likely iCloud locked by the original owner.
Pretending there is some easy fix for the iPhone is a good way to pawn a stolen, impossible to use device on an unwitting buyer. Just to let you know in case you don't, an iCloud locked phone is so far 100% impossible to unlock without the original user's password. Many many very smart people have tried and so far it's been completely bulletproof. Anybody saying they can unlock it for you is 100% lying, unless they have discovered something nobody else knows about yet.
If you want, you can try to fix the phone before buying it. But if it's a stolen phone, you're essentially meeting a thief with $300 cash in your pocket and your $500-2000 computer. Not worth the risk!
Phones sometimes will show this logo and it's usually as easy to fix as plugging into iTunes Most people are not so lazy that they would simply sell their phone before attempting this.