Answer:
Rachel had the most efficient social media strategy, because her photos have an air of professionalism, which is able to attract more customers.
Step-by-step explanation:
When hiring a professional photographer, Rachel put an air of professionalism and credibility in the photos she will put on social media. This credibility and professionalism will be very efficient in attracting clients, as it will give the impression that Rachel is a very competent hairdresser and that she takes great care of her reputation and therefore will take great care of her clients.
The photos of Lydia and Yoo-Hee, on the other hand, will give the impression of amateurism, since they are photos taken by the clients themselves.