I, on the contrary, think that PP is catering to her old CÉLINE clientele, and that a change in the strategy will be needed in the mid-term, if she wants to grow.
The whole project is interesting because she is avant-garde in the distribution (no brick-and-mortar stores) but at the same time is... nostalgic.
"To finally get the original" might make sense for an old Céline customer; for a thirty-something woman who buys Toteme, I doubt it.
Very accurate comment PDFSD about how high luxury works; I think fashion is a little bit different though, because the aura of a house can be damaged in a couple of years (cf. Gucci). It is not a solid value, almost by definition, because fashion is change.
Their story telling about being founded in 1913 or 1917 is a way to convince you that the jacket you are purchasing won't look passé three years later (it actually will).
The only house that you can really compare with Patek, Cartier, Rolex, Ferrari... is Hermès, and that by staying always a little outside of fashion.