Answer: Bypassing
Explanation: Bypassing is a communication problem which arises when two communicating individuals give different meaning to a word, phrase or sentence. It also arises when two individuals incorrectly assume that they have the same understanding of a particular word or subject whereas, they have actually ascribed different meaning to the word or subject.
In the given scenario, They both assume to have the same understanding or description of 'business casual'. However, they don't. Hence, the reason for the miscommunication.