Board Thread:Naruto: The Last Discussion/@comment-26010916-20150213211756/@comment-25632268-20150217093942

If this was the case then he should look like in Sage of Six Paths chakra mode at least for few seconds, before he separates himself from Kurama. And he is not, he is looking exactly the same whole time. Besides, he has no truth seeking balls.

http://naruto.wikia.com/wiki/Nine-Tails_Chakra_Mode

Good comparison between looks of different Ninetails chakra mode. Naruto from The Last is much closer to his Yang ninetails chakra mode that to Sage of the Six Paths mode. Here the difference may be attributed to either separating himself from Kurama or, more likely, to the fact that in The Last Naruto has complete Kurama, not only his one half.