Lionheads are a fairly new breed, so although there are breed standards it is still a pretty hard breed to perfect. You can get lionheads in the same litter who may be single maned, double maned or have no mane at all! Maisy is a lionhead with a very small mane...virtually none! She was fluffy as a baby and had a full mane but lost it.
If you look in my sig you will see Phoebe who is what you would have called a 'show quality' lionhead (if her colouring had been correct). Teddy is a lionhead who is very wooly (like spiders Toffee) and Milly is a lionhead x cashmere. She came from a litter of rabbits who all looked like the average single maned lionhead, however she definitely appears to have cashmere in her, that probably came from the breeding process way back in her lineage.