Answer by Skylinerw for How do I place a player skull with /setblock?

Unlike the item variant for skulls, the metadata value for the skull block does not determine type, instead specifying directional facing. The SkullType tag determines the type of skull.

Also unlike the item variant, the player information is not stored in a tag called SkullOwner. You'll want to use ExtraType instead, which transforms into the relevant Owner compound (see here for a description of that format).

/setblock -1393 66 1704 minecraft:skull 1 0 {ExtraType:"Illeloria",SkullType:3}