All Saints Spitalfields Dress size 8

All Saints Spitalfields faux wrap floral silk dress with black racerback lyocell and spandex tank dress attached underneath. Size 8. Attached photos for idea of sizing... hard to measure as material is stretchy and the silk part is flowy. One small stitch on black dress near armpit, cannot be seen as silk dress lays over it, please see photos. I would say looks like a size small.