Arianne's store is an example of Sole Proprietorship.
Sole Proprietorship is a business that is solely run by one person who is the owner of the company. He is responsible for all the liabilities of the company, yet the receiver of profits solely. The person who starts the business hires his team and get the activities of the business done by them with him. He is the one liable/receiver of all losses and profits.
In this example, Arianne is the owner of the business who hires employees to run her business. She is the Sole Proprietor.