This Pictish design mirrors the panel on the Shandwick (Chach A'Charridh) standing stone near Nigg (Ross and Cromarty), Highland.
Here's a link to a pic: http://web.telia.com/~u31118336/stone_struck/shandwick.htm
Canmore shows a nice photo serie of the stone (NH87SE 4).
Are there any other carvings around?
Cheers,
Jan