How can a metaphor affect a persons emotions?

In my opinion, at an emotional level there is no such thing as a metaphor or simile. If I say something is "like kicking a dog" my listener immediately goes to that image and responds emotionally to it. A public speaker can generate the emotion he or she wants from an audience by the choice of simile or metaphor. Consider:

"Drinking from someone else's glass is like shoving your tongue in their mouth."

"Drinking from someone else's glass is about as dangerous as shaking hands."

or

"A nurse who steals a patient's medication is a vampire."

"A nurse who steals a patient's medication is a prisoner of addiction."