[Mulder is used to that look. Though usually it's after a long involved case where he gets to add an "I told you so" or along those lines.]

You were making the universal "communicating with my mind" expression.

[There's an attempt to imitate Don's look. Definitely something a little more intense than Deep Thoughts.]

It was either that, telekinesis, or an attempt to blow things up with your mind, and since you mentioned a communication error...