The bat sleeve fashion style is named so because the sleeves of either the tops or dresses resembles the wings of bats at flight.
The bat sleeved tops or dress is wonderful to dress because it is usually made of very light material, even the embroidered ones are very airy and therefore suitable for the hot weather.
Pair the bat sleeve top with your skinny jeans a short skirt or shorts. The design can be off the shoulder, full neck, v-neck or even the round neck.
There is absolutely no rules when it comes to dressing the bat sleeves style because any kind of accessories matches this style. Experiment on what works best for your sense of style and tastes.