that's the whole point of a sub-race... are some of you even reading or thinking about what you read? a sub-race is either identical to what you have but just a different skin or an alternative version to what you have, i.e. a different look of the same thing.
with a half-elf you're going to be similar to a human (if you make his ears/eyreborws short) or an elf (if you make them long) or you can choose to go for varying in-between versions. I took the time to detail how the appearance would be too. It's a sub-race not a full race.