What is Google's plan?

So... seeing this image got me thinking today.
Motorola is kind of coming back under Google's wing, and we do know that an actual X Phone is in the works. This would lead me to think that the next Nexus might be Motorola-made, which would basically mean the creation of the first 100% Google phone.
Yet, rumors still talk about a X Phone that has pretty much nothing to do with the Nexus line besides leaked specs that make it seem really close to a Nexus 4. Why would such a phone make any sense, being Google and Motorola the same thing? Is Google trying to differentiate the X Phone from the Nexus via software, thanks to a skin or something? This meaning Google making a non Nexus device under the Motorola name? It sounds a bit weird to me, especially given the image above that underlines the strong relationship (or Motorola's Google's acquisition, better to say) between the two.

Anyways, I think that we will eventually get both the Motorola-branded X Phone and a (probably-)LG made Nexus 5, being somehow skinned the former.
But that sounds kinda stupid, doesn't it? I mean why not merging the two things and letting the Motorola-made Nexus 5 be real? Am I missing the bigger picture? Shed some light on it guys.

What do you think is going on over there at Google?