The human body is the ultimate expression of movement and thought. Creating the dancer's portfolio means exhibiting a collection of images that communicates your style of movement. Are you auditioning for a company, a school, a summer intensive? A typical portfolio consists of a strong classical ballet pose, a modern dance pose, and a creative pose. It is not about the number of shots you get, it's about "killing it" to get a few incredible images. You should expect at least an hour's in-studio shoot where you might stay with a first arabesque for 20 minutes if necessary.
Included in the session will be a close-up head shot since many auditions also require this image. If possible, your dance teacher or knowledgeable assistant should accompany you to the session for eyes-on accuracy.