Healing is a high aggro ability and seems to get the attention of mobs further than normal. When not expecting it having the mobs case after you just while recovering from a fight can be a startling appearance...

But we are enchantresses and we can bend the aggression of our foes to our benefit. By careful placement when healing you can do selective pulls. For example most foes appear to be lazy and will only chase you so far, so if you heal near a room full of enemies, then freeze just one as it chases you, you can run far enough so that the others tire of the chase and return to their post leaving you alone with just your chosen foe. A similar trick to the mind of your foes is to heal twice... once to get them to chase you and a second time after they have almost run back to their post to get just the ones that didn't chase you. You will need to be careful selecting your foes with such charming tricks though least you don't have enough mana left to fight against would be attackers.

The other use I've seen is being able to get our foes to chase you past the brave warrior you are teamed. As warriors are apt to stop them in their tracks. Since most enemies seem to be overly fearful of healing magic (perhaps it is painful to the undead), you can actually get the attention of enemies from further back then the warriors without requiring the rest of your party to journey forward into dangerous territory chosen by the enemies. So much better to fight them on your terms and ground of your choosing least they have a chance to regroup and bring too many into the fight.