Long sleeves with open shoulders make it especially clear on the red dress why sleeve length does not describe neckline height. The upper edge runs across below the shoulders, while the arms are covered to the wrists. A reflective surface, hanging side fabric and a leg opening appear alongside it. For a neckline comparison, set those extra details aside initially. The useful question is whether you want the shoulder area visibly open or would prefer the fabric to finish nearer your neck instead.
If you are seeking both long sleeves and a high neckline, state both wishes explicitly. This red example supplies only the first. On the real garment, test whether movement in the sleeves changes the position of the upper edge; a standing pose cannot answer that. For jewellery, look first at the open area above the edge, then add earrings or a necklace. Keep your hairstyle unchanged to see the effect of the neckline comparison. This makes the picture a precise contrast between arm and shoulder coverage, rather than labelling it high-neck simply because its sleeves are long.