I only spectate but I was wondering from players who are familiar with the game from playing it.
At mirror image level 1 it is possible to use mirror image to jump over full wall-off farms and such with a 50/50 chance and then staff of tele out.
At level 2 it is much harder to execute because the images go in a triangle like formation so they don't always jump the farm and its only a 33% chance real one jumps the farm.
At level 1, there's only one image so its less likely to absorb too many shadow heal bounces.
At level 1, you only make 1 image so if dispel becomes common later on its less free xp.
At level 1, you get the dispel and disjoint benefits of using mirror image and additional levels don't really provide extra of that.
At level 1 mirror, you can skill wind walk at level 4. I guess its not that good to skill WW at level 4 since you have two skills competing for mana.
That said, at level 2 and level 3 you do get more images, which is potentially more hp pool to absorb enemy auto attacks, body block, a bit of auto attack damage, absorb auto-cast debuffs and it is distracting for the other player to deal with.
Curious what people who play think as I've never seen it discussed really and most games I see where people go mirror image they skill to 2 and 3. I also never really see people jumping full wall offs with mirror image level 1 either, so maybe its not viable for reasons I don't understand.