"Zemnoy poklon" is a way of showing respect and honor to someone or something by bowing down and touching the ground with your forehead. It's a tradition in some cultures, especially in Russia and other Slavic countries.
So imagine you really admire someone, like your teacher or your grandparent. You want to show them how much you respect them, so you stand in front of them, bow down and touch the ground with your forehead. It's like saying "you are so important and special to me, I'm humbly showing my appreciation for you".
It might seem a little strange to you or unfamiliar - but it's a way of showing respect and gratitude in some cultures. It's important to respect different traditions, even if we don't practice them in our own lives.