What is a necessary piece of equipment for a cosmetician shop?

A magnifying lamp is essential in a cosmetician shop because it enhances visibility for detailed work on the skin, such as facials, extractions, and assessments of skin conditions. This piece of equipment allows cosmeticians to see the skin's texture and any imperfections more clearly, ensuring that they can provide accurate treatments and product recommendations to clients.

While other items, like a hair washing machine, mirror, or electric shaver, may be valuable in certain contexts, they do not serve the same specialized function in a cosmetology environment focused on skin care. The magnifying lamp is particularly important for achieving precision in skin treatments, which is integral to a cosmetician's role.