I found this laying around the internet, they look like they are scanned
from the Senjou no Valkyria 2 World Artworks book, they were originally
preorder telephone cards for Senjou no Valkyria 2 in Japan, one for the
Animate retailer and the other one for the Amiami retailer. The one on the left is RAITA's work.
The images are large, save them directly to your PC.