I very deeply doubt it. As you can see, the "look" of the first link is that of a faked badly balanced negative film while Velvia 100 is a slide film. Both appear to have been made at the beginning of the roll (you can bet the "app" only has the beginning of the roll). In both cases the effect used are different for different photos: you have the "slide fake thing", the "polaroid fake thing", the "Instamatic fake thing" etc and they are all mixed in the same twitter post; if in the first link the first image is actually a scan of a Velvia100, is it credible that the third is really instant film? That would mean Elisabetta Canalis dwells in all sorts of photographic processes. Don't know her personally, but frankly...
Generally speaking the "slider" on the "fake thing effect" is so high that the final result is not credible. The second series is even worse under this respect. And with only one Velvia shot in the series (lots of different "techniques" it appears).
Well, I would bet my jewels it's all "trickery and fake". And with different "special effects" taken from the toolbox in a random way.
EDIT: That' very likely the result of an Instagram filter. Instagram is an application (for iPhone and Android I think) that allows, if I get it right, an easy and "seamless" sharing of pictures taken with a phone through Facebook, Twitter or other such "social" networks. Included in the free price there are some filters which will make the awful mess that is supposed to imitate traditional photographic material. If it's bad, if colours are fake, if borders are uncertain, if there's a lot of flare, if the picture lacks contrast, then it must be "cool" as it is supposed to imitate analogue material even though it's even patent, in the game itself, that's just the effect of a filter.
That really makes Lomography look very serious by comparison . At least, with a Lomo you do a real bad job, not a fake bad job