The mirror reacted as expected: the reflection of D-00356271 (hereafter referred to as SCP-455-1) rose and stripped itself of clothing as it grew a second pair of arms and the size of its mouth expanded. It approached the mirror and began to strike the surface. D-00356271 was awakened by Dr. ???????? and the lighting increase sequence was initiated.
SCP 445-1 appeared to become increasingly agitated and began striking harder. Long, needle-like teeth erupted from its lips and began to circle around its oral cavity and it rose from the ground, allowing its legs to drift behind it as if blown by some unseen wind. Approximately 45 seconds after the initiation of the light-increasing sequence, cracks began to form across SCP-445's surface. After SCP-445-1's next strike, the reflective surface broke, leaving a hole into a room similar in appearance to the testing chamber, and SCP-445-1 flew through the opening at high speeds.
In the span of 3 seconds it grabbed D-00356271 by the head and feet and stretched his spine to the point of breaking and removed Dr. ????????'s head in a single bite.
Alarms were sounded and security was dispatched to the testing chamber, however their entry into the chamber was met by entry of similar figures in the room visible in the hole (SCP 445-2 through SCP 445-27). Gunfire proved effective at stopping these beings, though 10 members of the security detail were lost in the process, mostly by means of massive internal injuries or lacerations to the face and throat.
Recovered bodies of the reflected versions of the security team proved that their guns were inoperable and attached to the hand as if a part of the body. Upon the deaths of SCP 445-1 through SCP 445-27, the bodies of all but the reflections of the dead security team and SCP 445-1 vanished and 15 new creatures entered the reflected room, to be cut down by gunfire.