Participants are relied upon for providing their own perspective of the service through this tool. Mobile ethnography is similar to cultural probes but less structured in that the space or "culture" is not so defined. Researchers are even more removed and users choose how to structure the research themselves, including how they document and interact with the service.
Provide users with technology (phone, audio recording, etc)
Have participants document their own touchpoints
Mobile ethnography can be applied in limitless ways, and used to generate perspectives from all kinds of stakeholders through technology - whether internally or externally. Instead of trying your best to ask the right questions or put yourself in the users mind, they essentially do it for you when given the appropriate tools.