A mannequin monster transforms many other people into mannequins using eye lasers.
There's a fairly decent number of people turned into mannequins in this episode, each with different poses. The first victim is found on an alley in the middle of the night. She appears to be angry. The next victim is the only woman we see actually being transformed by the monster. The laser hits her in the face. The transformation starts at the impact site and spreads outward. She has a surprised look on her face. Later, we see victims in a department store that appear to have been going about their daily lives when they were transformed.
The mannequins have a very tan look to them that is darker than their usual white selves. They lack irises and pupils. When the monster is defeated, all of the mannequins steam and fade back to normal.
The original manga series which the anime is based of. Several good shots of the mannequins are available in the manga, same as the anime. However, the anime has the exclusive transformation scenes of two major characters compared to the manga.