Vintage 70s Sundress Nightgown Floral Smocked S

I’m not exactly sure if this 70s dress is in fact a dress or a nightgown. I know I had some dresses like this back in the day so I think it could be worn either way. Smocked top and shift style. cotton and polyester blend. That is the only information on the interior tag, no brand name or size, but it is featured on my size small dress form for scale. No noted flaws. Lay flat measures 9.5 inches armpit to armpit when relaxed stretching to 23 inches without much resistance, 24 inches straight across the waist and 28” across the hip.