I just watched it. It shouldn't be compared to the Audrey Tatou film (which I'm afraid I never finished watching). It is a bit of fanciful fun.
The French language turning into (present day) vernacular English, Keira Knightley's makeup (and her charming but distinctly un-Coco-ish self), the obvious use of fashion models as actors; these things could throw a viewer out of the story; or instead, as for me, they could remind us this is not a literal depiction of Coco but rather the idea of her, as we might fantasise her and her beginnings. The not-realness reminds us she is now part of our collective dream. What better way to silently suggest the power, dominance, and ubiquity of the Chanel brand. Seeing the film this way, I see it as a very long ad, and as such it comes off as more than it is, not less (which if viewed as an attempt at authenticity, it would be).
The unreality, and hence frivolity, is a celebration of fashion-as-escapism (like most good fashion shows or ads). This provides the perfect foil for the one deadly serious thing in the movie - the CLOTHES.
