Twiggy,
Seen horizontally like this, you're to good looking to be suffering, so this is indeed a metaphor. There's no graphic content to frighten anyone! instead we are asked to look at you and think of "what if". It refers to our fragility and our risks in living. It does this with no pain. It says, you had been wounded earlier in the day, so the blood is dried then you have been laid down as a wounded actor. This is essentially a crucifixion image divorced of region. It has death and life and "acting as if".
Asher
If the blood was draining downwards, i.e. to the right side, it would get a more frightening feeling perhaps since it would be obeying biology and physics.