What do uniforms symbolize for Keiko in the novel, Convenience Store Woman?

Uniforms symbolize conformity. When Keiko starts working at the convenience store, she is given a uniform, which allows her to homogenously blend in with those around her. She takes great comfort in how this uniform equalizes everyone in the store, regardless of age, gender, or nationality. The uniforms represent the transformation that Keiko goes through when she becomes a convenience store worker.