A sitter photo session is a milestone mini session when a baby is around 5-9 months old and can sit by themselves. Babies are very interactive at this age; they smile easily, they giggle and make adorable faces. Sitter sessions are generally short since a 6-month old baby has a short attention span. It usually involves 2 setups with few different accessories for each setup. I have a lot of custom made props for a sitter photo session, so I can assure you that your baby will be dressed adorably.