It's confusing when it comes to complex licenses that is why all photos on Creative Vix are licensed under the Creative Commons Zero (CC0) license. This means you can copy, modify, distribute and perform the photos. The pictures are free for personal and even for commercial use. All without asking for permission or setting a link to the source. So that attribution is not required. All in all the photos are completely free to be used for any legal purpose.
The CC0 license was released by the non-profit organization Creative Commons (CC). Get more information about the license on the official license page.