Ok, now I can see the pictures on my desktop computer. As far as I can tell, it's Vache Natural, and the grey watermarks look exactly the same as the ones on my VN Kelly. Not sure why it would be grey on VN but brown on Vachetta, but the leathers may be processed differently. Your bag may not have darkened much because it hasn't been used much. My Kelly is about 20 years old, and it is about the same color as your Plume. It sat in its dustbag in a closet for 5 years before I started using it regularly. It darkened a tiny bit over those five years, but the difference was only noticeable when I compared it to photos from the day I bought it. Now that I've been using it regularly, I can see much more change in color, especially on the handles and straps where my hands touch the leather a lot, BUT it's still not very dark.. Blackrock or Hermes Saddle baume will hasten the color change, but unlike with Barenia, the change comes slowly. I've found that the leather patinas just as nicely and quickly from contact with your hands (handles, straps, the rest of the bag if you routinely rub your hands all over your bagSo it wouldn't look like watermarks on LV vachetta? Saw docride mentioned in the past that VN had some semi-finish, so I guess it's possible it might not patina much? But it really doesn't darken even after blackrock, only the scruffed parts...
).
that it wouldn't change color so soon, and half 
that any scruffs/rubbing off the semi-finish will be very prominent. But glad the mystery is solved, and yes, I do occasionally rub my hands all over my bag 
