Invisible Locked Coins?

First time posting here! I am new to the coin system, so I was just curious after gifting some coins and reading after-the-fact about locked coins. Are locked coins visible by the receiver of the coins? How long does it typically take for the receiver to be able to few the gifted coins?

I've read 72 hours for the coins to be "unlocked", does that include to be viewed as well?

Thanks!