It can be difficult, but try to keep a positive mood after a negative review. Being visibly sad or sullen on the job can reflect poorly on your work, making you look like an under-performer even if you are taking other steps to improve your output. It can also call unnecessary attention to yourself, prompting your coworkers to wonder or ask about your sudden change in mood. Since supervisors know that their employees' morale can affect the business's productivity, this can get you in even more trouble.