A 248 This is an excellent question but to be honest, I don't think there's a simple RAW answer to it. There have been long contentious threads about how Mirror Image works or doesn't work in a particular context. The spell description doesn't directly address this.

"the duplicates move with you and m im ic your actions"

Based on this, I would say the images are dodging also and thus imposing disadvantage on attacks. However a less lenient DM may very well interpret that differently. For instance, he could say you're dodging attacks directed at you and not at your images, or that even if you try to dodge an attack directed at an image, it wouldn't work quite right because it's in a different position and the same movement might move it into the line of attack instead of away, for instance.