Johnny Cupcakes was unique primarily due to its branding and marketing strategy, which created a cult-like following around its products. However, from the choices you've provided, the correct response that highlights a unique aspect of Johnny Cupcakes compared to other t-shirt companies is:
Each Johnny Cupcakes t-shirt could be turned into compostable material.
This focus on sustainability and eco-friendliness set it apart in the fashion industry, making it not just a t-shirt company but a brand with a mission toward environmental consciousness.