Answer:
It is most likely she has taken LSD.
Explanation:
LSD is a hallucinogen, which means it creates hallucinations (seeing, or hearing things that are not there, for example). This drug does <em>not allow one to separate fantasy from reality</em> and it affects the individual's perception.
LSD takes the place of serotonin (a neurotransmitter) on the brain, which is in charge of regulating one's mood. It also makes the brain <em>mix the sensory pathways</em>, thus creating a temporary synesthesia, such as hearing colors.
In this case, Carena has had perceptual changes and she is hallucinating butterflies, seeing objects glow and change shapes and even having a sharp look. It can be concluded that she has taken LSD.