The Tunnel Scene from Willy Wonka & the Chocolate Factory

Probably one of the most screwed-up moments in the history of kid's films.
Can anybody give me reason what purpose this scene serves?

• #film_animation
• #tunnel
• #scene
• #willy
• #wonka
• #and
• #the
• #chocolate
• #factory
• #1971
• #retro
• #odd
• #freaky
• #scary