Recently, a friend of mine had a Skype interview for a job she had applied. She had received an email, telling her that a laptop with a camera was preferred, and that the interview would be just a couple of minutes, as she had previously had another interview.
During the Skype interview, she received an Excel file, and was asked to do some kind of short assignment, so to speak. Normally she was familiar with Excel, and what had to be done for that assignment. However, she was caught off guard because she wasn't told there would be any Excel assignment to do from her laptop, and she was actually using a MacBook which didn't have Excel installed.
The assignment was basically about summation, and she explained with her words what had to be done, but the interviewers did not seem to be pleased with the fact that she didn't actually do it in Excel, but merely explained it (although she did explain that she didn't have Excel installed, because she wasn't told).
To me, this doesn't sound quite right; at the very least I'd expect to be told what to prepare for an interview. What is your opinion on this?