Is it permissible to wear a decorated garment under the شرعي (Shara'i) dress, then remove it upon arriving at a women's gathering and suffice with the embellished garment?

A woman is permitted to wear decorative clothing under her legal hijab, so that she can display it at women's gatherings after removing the hijab, provided she covers her 'awrah (from the navel to the knee) and ensures there are no foreign men or photography.