I love this post card. It shows the castle with a cluttered exterior, obviously still used by the townsfolk of Penrith. The wall transcending the castle mound and the moat is interesting, and possibly suggests that at the time the photo was taken, the grounds were grazed by local farmers. The wall is long gone, though a scar can clearly be seen on the more modern photo shown below.
Above. 2011 photo, demonstrating the remarkable lack of decay since the postcard from 1906.