You gaze at the figure reflected in the glass. It looks like you, but something is very off. You look slightly older, with stubble adorning your usually smooth-shaven face. The most striking difference, though, is the clothing your reflection is wearing. Rather than the comfortable hoodie and jeans you normally wear, your reflection is in the full uniform of a police officer. Navy pants, light blue shirt, and hat; the entire package right there in the mirror. You look closer and realize that not only are you wearing the uniform, but your frame is huge. Instead of the not-too-out-of-shape build you have now, your reflection looks like he spends every free moment at the gym.
"How good is this illusion?" you think to yourself. You want to see how detailed this trick is. You flex your arm and see the cop in the mirror do the same. You flex some more, impressed at how realistic the figure follows you. You're having so much fun playing with the effect that you don't notice that you've knocked your hat off right away.
Wait...
Your reflection's hat fell off, so then why is there an identical, if reversed, police officer's hat on the floor in front of you? You look back into the glass and still see the buff cop, but his hat is still off, revealing close-cut hair. His face looks as confused and frightened as you feel.
Preparing for the worst, you look down at your chest and see well-defined pecs covered by the blue, button-up shirt of a police officer. You run your meaty fingers over your now shorter hair. You have to face a strange truth, the mirror actually changed you!