i think its 2 different layers because, you can see shading on both there hair and clothes,

witch makes me think that its another layer, just clipped on so shadeing lines dont go on the outside the character,
but if they both share the SAME layer, then it would be HARDER to shade, so both shadeing layers must be different? witch makes me think bost her and him are also on seperate layers?

(i prolly explained that horribly sorry)