“Sometimes I can't figure designers out. It's as if they flunked human anatomy.”

Simplified Meaning:

When someone says they can't understand designers and it's like the designers didn't learn about the human body, they mean that some products or clothes are badly made for people to use or wear. Imagine buying a fancy chair that looks amazing but is really uncomfortable to sit on. The person who designed it might not have thought about how people actually sit. For example, there are some shoes that look stylish but are so painful to walk in because they don't fit the shape of a normal foot. This happens when designers focus more on appearance and forget about comfort and practicality. If you are a designer, try to think about how your creations will be used in real life and make sure they are comfortable and functional, not just pretty. By doing this, you make sure people enjoy using your products and find them helpful in their day-to-day lives.