I am going to say no, and here is why.

Minor illusion allows you to mimic simple things. However it does not duplicate effects. Although a mirror is a simple thing, the images it reflects are or could be very complicated. Additionally, they'd need to mimic what's being reflected in mirror image.

I think you could use minor illusion to mimic a portrait, but s mirror I think is too complicated.

Ok, I am pulling out the boom to refine my answer, but that's this is still the basis.

I am going to say no, and here is why.

Minor illusion allows you to mimic simple things. However it does not duplicate effects. Although a mirror is a simple thing, the images it reflects are or could be very complicated. Additionally, they'd need to mimic what's being reflected in mirror image.

I think you could use minor illusion to mimic a portrait, but s mirror I think is too complicated.

Ok, I am pulling out the boom to refine my answer, but that's this is still the basis.

Update: nevermind, shadow players answer is good.