I think you may already understand to see this picture that it's a day of festival. "Pohela Boishak" is the first day of Bengali new year and "Boishak" is the first month of this Bengali calendar. That means "Pohela Boishak" is the first day of Boishak. This day also known as Bangla Noboborsho to the people of Bangladesh.
On this day, different types of art are drawn. These are called "Alpana". These Alpana can be based on anything like different types of flower, different types of design of different things, different types of story etc.
Food menu of this day is different. People like to follow there tradition. "Panta-Ilish" is the main attraction of this day's food menu.
A village fair is organized every year on this day. This village fair is known to the people as "Boisakhi Mela". Two classes people come to this fair, one who comes from far way to sell his/her product and on the other hand, who comes to buy his or her product. Most of the products are hand made.
However, this day is a festival day for the Bengali people. People like to start their Bengali new year with follow their tradition. It's a well known day across the world nowadays.
