A high-neck black mini dress shows fine vertical ridges from the upper section into the short skirt here. The shoulders are gathered, with the long sleeves becoming narrower along the arms beneath them. A tied belt defines the waist and its ends hang over the skirt front. Bare legs are visible below the short hem. With the feet outside the frame, the picture chiefly helps compare upper coverage and the extra line at the waist.
If you want to add tights, try their waistband with the tied belt and intended underwear. Sit down in the combination and check whether the pieces lie comfortably together. Simply tightening an uncomfortable arrangement is unlikely to answer the fitting question. Another waistband height or pair is an option to compare while actually wearing the dress.
Treat the dress ridges as an existing pattern and begin the lower colour comparison with plain hosiery. Add your shoes in a full-length view next. This lets you choose coverage without introducing a new leg pattern and a different shoe shape simultaneously.