The straight strapless mini has a relatively clear upper line and a short skirt that flares away from the waist. The photographed outfit pairs it with dark tights, dark shoes and a small bag. Reflections are spread over the dress, leaving the bare upper chest as a quieter area. This makes it a useful comparison with the heavily textured neckline in the long example.
For a similar garment, assess the top edge while sitting, reaching forward and returning upright. Start with the underlayer you actually plan to wear. Notice whether you repeatedly pull the neckline into position, and discuss any proposed adjustment on the real item rather than choosing a smaller size solely to hold the upper edge.
Then test the short skirt with the intended leg coverage and shoes. Sit without arranging the flare into the pose shown in a product photograph. Carry the bag normally and check where it rests beside the surface. If you want jewellery, add one piece after this fitting; the open upper area gives an option for an accent, rather than an obligation to fill every visible space.