Bing’s Tuesday homepage was a tribute to a celebration in Japan. 
It was there for a reason, as the team blog explains:
We were celebrating as Bing Japan removed its beta tag, launched a new product feature and became a contender in the Japanese search market.
The launch was complete with launch event! Fans lined up and laughed the day away as Yoshimoto’s (Yoshimoto Entertainment Company) comedians gave live, impromptu impressions of Bing while highlighting some of their favorite Bing features.