The negative look stops the behavior in the short run. So it is punished I think, but at the same time punishment is not known for being a long standing solution. As in the behavior will stop for a short time until Esperanza expects it. 
In summary it will lose its power of stopping the behavior once expected. 
But that is simply a guess. 
If you are looking for an overall explanation. 
Rationale: 
+reinforce --> no bc it is not increasing the behavior. 
- reinforcement is when something is removed that increases the behavior, I think. 
- punishment is something out side of the situation. 
- such as Pavlov non connected 
- yes it is threatening, but that may not explain the behavior connection? 
-I would verify this with research, but apparently that is against the rules?