Hall of Reflection… Say What?

So I'm probably not into the lore of WoW enough to understand the reason for which this dungeon has been named the way it has. But I take issue with it. I guess it's perhaps because the two fights "mirror" each other at the beginning.  

Anyway, that tangent aside, I healed it last night for the first time—actually, I healed all of the heroic  ICC 5 mans. The entire experience was rather fulfilling. I got a nice 235 trinket, and some good experience despite the lag I was facing. After the never-ending waves (10 Blizzard, really?) we continued on, and I wiped for the first time when doing that run at that part of it. One of the pickups was like "I've never survived this last part--it's so hard." And sure enough, we died.  I was confused, what had I done wrong? And then it hit me—in the past when I had run it with my guildies, we kept ahead of the Lich King—but this tank wanted to tank behind him. After we had all rez'd and were back and ready to start the fight, I begged—"Please, could we stay in FRONT of the LK?" "I guess," the tank replied. "We could try it."

So we did, charging forward. And it worked. We completed it within minutes, quickly traversing all of the barriers, and ending right where we needed to. When we had finished, the pick-up had all received the "We're Not Retreating; We're Advancing in Different Direction" achievement.