WTF?

My boss' boss emailed me with some questions today. He could have just called my boss, but I think he wanted to communicate with me. I don't know why. Either he is annoyed with my boss or he just realized I am not feeling very friendly toward him these days. He followed up the email conversation we had with a visit to my office to explain why he wanted the information. Totally unnecessary. He can ask me anything anytime. He is an executive. What is he trying to achieve? I don't know.