There was a two stage process. One interview was conducted by the employee that I was going to be covering for, the other by the local VP.
In both cases, the interviews were informal, friendly and mostly focused on determining whether I would be the right fit for the role rather than having the technical capabilities for the job. A number of clients were outlined, along with the nature of the company's interaction with said clients. One particular client was singled out for attention, as it was the one that I would most likely be having an immediate interaction with.
Throughout the process, I felt that they were watching my reactions to what they were saying rather than trying to get rote responses to set questions.