All labs have a demo component, and most have a design component.
Moreover, please note that TAs will not grade your code unless you have demonstrated it in the appropriate lab session.
Because your design is graded and turned back to you, the code need not follow your original design. Also, you will receive a standard design prior to implementing your labs. The idea is for you to consider changes to your design that will ease implementation.
Just as in an English composition class, it is very important that you take the time to make sure that your solution is clear and well-explained. Follow the CS101 Style Guide and strive for elegance!
Also, be sure that you understand the Late Policy and the Policy on Collaboration.