Emotion-Detecting Crosswalk - (Speaking > Unusual Situation)

You are walking in the city and come across a crosswalk that seems to change its signals based on pedestrians' emotions. The crosswalk uses advanced sensors to detect people's moods and adjusts its timing and display accordingly.

Call a friend who is interested in urban technology. Describe this unusual crosswalk system in detail, explaining how it works and discussing its potential benefits and drawbacks for city life.