You are assuming, based on third hand information, that the employer has just unilaterally decided to give one employee privileges for no reason other than that they choose to. While it's within supposition that this is the case (and it would not be illegal even if so) it is far more likely that there is a reason to which your friend is not privy. This could involve medical reasons involving a family member, disability issues, a special work related project, or a dozen other things. Massachusetts, which is my state as well (and also Blue's), is an employee-friendly state.
If only one employee is being allowed to work from home or provided with paid travel (btw, MA law REQUIRES certain types of mileage to be paid - it's possible this employee is the only one who is making the type of travel which fits the requirement) and all other employees are not, that suggests that there is something specific to the employee's situation which has triggered the employer to permit this, rather than just playing favorites. If some employees were being granted privileges and not others, that might indicate favoritism of some kind (which still would not necessarily be illegal). However, where it is only one employee, that says to the HR manager in me that the employee is on FMLA, has an ADA issue, or has some other personal situation which means the employer either is required to, or has opted to, accommodate the employee's situation. Once again, your friend would not likely be aware of, and is not entitled to, know the employer's reasoning. The employee in question has certain rights which, depending on the reason for the accommodation and other details, might be violated by the employer's explaining the reasons why to the population at large.