Something is definitely wrong with the one on the left. I call this figure wearing a Nightmare Nightgown. Not that she's actually wearing a nightgown but it resembles it. If you find yourself wearing this dress, it's simple to solve.
The right figure is on the RIGHT. Dresses today are fun and shorter. I suggest a length of two to three inches above the ball of your knees. That gives you extra height. Next, cinge the waist with a belt. Try putting the belt just ABOVE the navel. It's a secret to adding height. Belts also gives accent to a dress, especially if it's monotoned. Try experimenting with a lively colored belt.
These small simple details change the overall look you are sporting. Do not underestimate cuts and accents. It can save your (love) life. Joke! But it changes your look and your look changes your outlook!
There! You shall find yourself very different from your nightmare.