It is due to the subtle nuances of her character. You see, Elphelt Valentine leads a tortured existence on account of being a fictional character who realizes she is fictional, and desires the only true freedom a fictional being can have from the mockery of their existence, which is total death. However, she also desires to free all of the other beings in her universe of their miserable, predestined existence, and she attempts to exterminate all of them in a confused act of mercy. Although she can hide her cold gaze, and you can shake her hand and feel flesh gripping yours, and maybe even sense that your lifestyles are somewhat comparable, she is simply not there.