The third one was apparently infamous, known as SCP-173, and that was worrying for Shadow. She was lead into a room with two other people and given the instructions. They all needed to keep their eyes on the SCP and call out when they must blink. After everyone was settled they had the men turn around and Shadow close her eyes. 

Within seconds there were two cracks and Shadow opened her eyes to the men dead. She turned around and the thing was right behind her, causing her to scream and then apologize. After some more trials or whatever Shadow was bored, so she decided to have some fun. Ignoring orders and warnings she walked up to 173 and gave him a hug.

"Your really cool you know that. And you do such a good job with patients."

At this point, the conclusion was certain so they pulled her and she was put back in her cell.