I don't own a Steam account (so far) but from what I know these should ways to gift the game to another Steam user. The strange thing anyway is that they cost less than half the price of the full game.
I thought that if someone is interested to get the game on Steam but without caring for the incentives of the pre-order, could use this way for "gifting" to him the game (planning the thing with another Steam user).
An user that got DoA5LR in a such way said me that, at least in this case, you receive through mail a code that you can redeem in any account (so even in your main one of Steam, without need to create a different account). Btw I hope to not spread any misleading infos being them not directly from my hand.