What do you think of when you look in a mirror? Is it how you look? That would be the first thought, yes, but do you ever let your mind wonder off, letting you think that your reflection is more than that? No, that's absurd and ridiculous. It's just your reflection, isn't it? Do you get that feeling that someone is watching? Of course not. Your reflection is your image in glass.
You automatically trust that it can't do you harm, but you shouldn't. It's not really you in the reflection, and it can't be trusted. Take a closer look, focus on what's supposedly you, and if you're keen, you will notice it messing up in its movements. When you catch this irregularity, do not give any sign that you saw its mistake. Just walk away and act as if nothing happened. If you let it know its mistake, its skin will turn to what looks like burnt leather, the eyes will melt away, and its face will contort into a sinister grin, showing sharp teeth.
The background will darken. The only thing visible is what seems to be human flesh that has been stained with blood. The background decorated with entrails. It will be the last glimpse you will see in the mirror before the glass starts to ooze blood. When the mirror is fully covered in blood, a hand will appear through the blood, reaching out to you in a beckoning manner.
You know you should not grab it, but you no longer have control at this point. Upon taking the hand, you will feel a sharp pain shoot throughout your arm, followed by darkness. Quickly upon regaining consciousness, the distinctive smell of blood and sulfur will attack your olfactory senses. There will be only one thing visible - the mirror to reality.