I think that this is probably after the Queen kill’s Snow’s father because the Queen is wearing black and before that she didn’t.
Good catch! Unless she wore black before marrying King Leopold.
The Lamp could go either way. Maybe Rumpelstiltskin had it before King Leopold, or maybe after.
Perhaps what caused Evil Queen and Rumpelstiltskin to be such enemies was because of having traded the curse. Or maybe she stole it from Rumpelstiltskin.