I'm posting here to make it clear people to know how to do it.

1- First connect both computers in the same account (I guess doesn't really matter if the computers are in LAN or not... what matters I think is getting connecting from the same router)
2- Activate Remote play and let Steam recognize both devices, if one download shows in both computers and it means both computers recognize each other.
3- Disabling Remote play or enabling it doesn't make any difference, now both computers recognize each other and when downloading anything for example a game from computer 1, it will be transferred to computer 2.

This feature is actually helpful for people using Windows 7 and Windows 8 since certain games can't be finished due to lack of sandboxie in the Steam client.