A bit difficult to comment without seeing the work and knowing how it compares with other work in your portfolio and a general idea of what level of experience you are at.
I wouldn’t build out the project to be more than it was, but showing as much process as possible is usually the best bet. With footwear in particular, you should be use your role on the project was clear. I’ve seen some portfolios with nice finished photos of products and later found out all the designer did was pick colors and materials.
If you did take a design from sketch to spec to production (did you also do the development?) this is still good to show, even if the final product isn’t that exciting. That being said, you can usually make a not so exciting shoe still look good with decent photos. Is it an issue of poor photos?
Don’t forget you can also beef up your portfolio with self-directed projects that compliment your professional work with more exciting designs showing similar process.
R