reminds me of the cover for "let us prey" by electric wizard
if you want more specific design details you'll really have to post what genre of metal they are
for example (at least for album covers) black metal bands are bound to have lots of pictures of demonic beings and inverted pentagrams on them, death metal bands invaribly have a picture of the grim reaper or someone dying on them, power metal will have a really cheesy looking dude on a horse holding his sword above his head looking completly gay (no offence at all to homosexual's but are you saying you wouldn't hit on him if you were), pregressive metal will have something which looks like it came straight from an esher picture, thrash will have various things on them generally dependant on the lyrical content and doom metal are likly to have any thing unless it's from the stoner doom genre in which case it will have some kindof drug reference
so that's my run down of what metal symbols look like but it probably dosn't help you except that i will tell you it is a really cool pic