Custom spells

I don't see the need for a Mentem requesite, the item does not have to read the mind of the user, simply the user activates the effect (by touching the frame with his index finger for example) and uses it to create the image just as he does when he casts a spell. Maybe a finesse roll should be required for particular complex images? A Mentem requisite is needed when the effect creates something that resemble a limited independent intellect, as for example in "The shadow of human life" spell, and this is not the case.

Also, why do you think this effect could create only a limited number of images? The phantasm animal spell in AM5 book can create any animal up to size +1 (not a particular kind only, but all types of animals) and the mirror's effect is more complex (+2 magnitude) then that.

Regarding the range I was indecise myself between personal and touch, I resolved for the former because the image is created within the mirror but I'm not totally sure about that.