Keep in mind the platform. This isn’t an attack helicopter, it’s a little drone. The more weight it carries, the less range it has, and it doesn’t have much capacity to begin with. At most a pound or so. As a result, these little bombs are small fragmentation grenades. The explosion itself doesn’t do much damage, in this case it blew the soldiers hand off because it was a direct hit, but that’s pretty unusual. Most of the damage comes from shrapnel, the explosive is wrapped with metal and bits of that metal will go off at high speed in every direction like little bullets. The shrapnel doesn’t produce much obvious damage when seen from the air, not compared to a normal bomb that sends stuff flying in every direction. But it is quite lethal.