The lookup says unkown, after three tests with SoS and using cautious attack I have come to the conclusion that it only defends 1 dark.
The reason it shows only 1 icon is because your defence boost is the 8 boost while your opponent's strength boost is the 125 boost. It would be most helpful if you could test it on pets with even strength and defence boosts.
Well if anyone with 8 defence boost would like to battle me, look me up. My UN is congratz.