Stun vs damage over time

Stun is the damage when attached, which is the skill's "damage %"...afterwards they take damage over time, which is labeled as "X Additional Damage every 3 Seconds". The stun part is when a monster is snared, and only last during the skill duration. Both are affected by the monster's def/prot. I'm not making heads or tails out of what I read since it keeps talking about the after effects, rather than the skill's stun.

I'm not too sure about a lot of this, but I know what I'm talking about...I think. Updated the video to show the damage over time.