The New party summon trick

I believe the idea is that if you are fighting a boss with few people and are about to die, you can summon yourself so that you are no longer fighting the boss, and can rest/change weapon/armor etc. That way, few people could take down much stronger enemies when there is no availability of more players. For example:

You are fighting a boss, with one other friend, and for some reason you are targeted more often, and are nearly dead. Now, if your friend summons you, you can stop to rest while your friend holds off the boss. But, since not everyone is perfect, your friend might not notice you are low on health in enough time for you to get the summon and then rest. So, it allows you to summon yourself and take the responsibility away from your teammate/friend. Then, after you finish resting, you can hack away again.

@Above: I believe you will be summoned and stay in the same room you are in.