Discovery Sport - uneven brake pads

[Runnyg]

I've just noticed on my 12 month old Disco Sport that the rear pads don't seem to be the same size as the discs - see attached. The outer 12mm or do of the disc doesn't appear to come into contact with the pad at all.

The vehicle recently had its first service and has covered around 6,000 miles.

Never seen this on a car before - is it common or maybe a fault of some kind ?