None. Same questions and bar for case and fit
Format of the interview is same. Cases are same too.
However, sometimes performance expectation can be different. While in terms of logical thinking and critical reasoning type of aspects expectation is same for both MBA and undergrads, technical knowledge expectation can be higher for MBA students. For example, it might be okay if undergrad student is not familiar with a valuation but it would be less acceptable for MBA student.
as mentioned, the structure of the interview is the same, however the expectations are different. For a post MBA with previous work experience, there will be expectations of more “technical knowledge” and business sense, stronger examples for the fit part and better communication.
Long story short: the interview parts and competences are the same, but the bar is higher with MBA candidates due to their experience.