SRD:
Area: Cone-shaped emanation
Using the foul sight granted by the powers of unlife, you can determine the condition of creatures near death within the spell’s range. You instantly know whether each creature within the area is dead, fragile (alive and wounded, with 3 or fewer hit points left), fighting off death (alive with 4 or more hit points), undead, or neither alive nor dead (such as a construct).
The area is a cone, each creature is every one. Does anyone consider the figments from mirror image to be the same creature as you are? If there are 20 creatures in the area do you simply know that 10 are alive and 10 are fighting off death? or can you say, 'bob is alive, jill is alive, billy is fighting off death, susan is fighting off death...'?