Pros
I really enjoyed working at Sephora. There's constant opportunity for learning and growth in a range of fields: artistry, customer service, sales, etc. and good opportunity for upward movement in the company. Whether you come in with a specialization or not, management and education do a good job of directing and training their employees to help you achieve your personal goals with the company.
Cons
Pay is low compared to what other makeup artists make in the industry. There is also an entire new vocabulary you will have to learn when starting, which can be a bit daunting (i.e. sales floor is the "stage", customers are "clients", departments are "worlds", etc.). Due to high internal theft in the company, management can be a bit intense about employee conduct with personal cosmetic items- ex: all makeup items brought in must be scribed with employee #, in a clear bag, etc. (though some of this is standard practice in cosmetics retail).