Google Nexus 5S is a Slight Evolution of the 2013 Google Flagship

We have written quite a few posts about the new Nexus phones, the supposed LG Nexus 2015 and the Huawei Nexus 2015, but about a Nexus 5S? This one is supposed to be a slight evolution of the Nexus 5, sort of like the iPhone 5s was for the iPhone