You can see those damages on the Combat tab. If you see condition damage ; for instance , Burning , Confusion , Torment , Poison or Bleeding , which is higher than the direct damage , your enemy's build is condi. On the contrary , providing that those condition damages are lower than the direct damage he inflicts on you , his build is power. Thus ,yes , it is possible to identify whether your enemy's build is power or otherwise during the combat.