Actually, I just noticed that is a slightly different holster to that one. The one in that image is their
level 2 holster, rather than their
level 3 one. This image is from the public "unveiling" of the British Army's new pistols/holsters, but I think these level 2 ones might just be stand ins as in any images of them being used they are the level 3 ones (
here,
here,
here and
here).