Unveiled in 1972, this bronze statue was constructed to celebrate the Great Leader's 60th birthday. This is what the Mansudae Grand Monument looked like prior to 2012, when the monument went through some changes and additions. No visit to North Korea is really complete without a visit here, as this is one of the most revered places in the country.
Given it's significance, there is certain etiquette that must be adhered to, lest you want to go from being a guest of the country to an unwelcome guest. Generally, several people in the tour group should buy flowers to lay at the feet of the statue. Once the flowers have been laid down, the entire group (in a line) will bow in respect. The tour guide will help coordinate all this, so as long as you follow along there shouldn't be any issues.
While on the subject of respect and significance, if you want to take a photo of the statue, you must be sure to include the statue in its entirety, and not zoom in on say just the head for instance. It would be hugely insulting to do so, and could see you getting expelled from the country!
Statue of Eternal President Kim Il-sung