Tourists waiting outside of a home to visit.
People standing outside of a house.
Tourists are people, standing outside is another way to say waiting and house is a synonym for home.
Tourists are people, so if tourists are outside of a home, that means that people are outside the home.
"People standing" rephrases "tourists waiting", and a house is another word for a home, so the people standing outside of a house must be tourists waiting outside of a home to visit.