A man with a blue and white backpack and black jeans and jacket walks by a large monument surrounded by a gray fence.
A person is strolling with a bag.
A backpack is a type of bag or baggage; a man is a person; strolling is a form of walking; a man with a backpack who walks means that a person is strolling with a bag.
A man is a person, a backpack is a bag, and a walk is also called a stroll.
The man with a white backpack walking by a large monument is the person strolling with a bag