What changes between looks?
A convertible wedding dress changes through a removable or repositionable part. Sleeves alter coverage around the arms; an overskirt changes the lower outline and may add train length. The category describes a mechanism, not a fixed number of looks.
Two different mechanisms
Milos has detachable lace sleeves resting off the shoulders above a fitted lace gown. Its coordinating cape adds another airy outer layer behind the narrow skirt. Jeimee starts with a closely fitted lace column and gains a full satin overskirt that fastens at the waist. The change on Milos is concentrated around the arms and back; Jeimee alters the skirt’s side and rear volume while leaving lace visible at the front.
A detachable overskirt is therefore only one route to a changeable gown. Compare the base and layered versions of a specific dress at a fitting, including the waist attachment and the view from behind.