Rosette refers to a decoration consisting of strips of ribbon, leather,, etc designed in a concentric circle to resemble a rose. Likewise, Rosette is described as a fabric formed into the shape of a flower that is generally used as embellishment to add a more feminine look. Rosettes can soften a style and add interest to areas you want to highlight.
Rosettes are mostly sewn into a dress but designed in a way that it can be easily removed for purposes of washing or cleaning and re-sewn back.