Well, it does to a point. A clip on mic that's only an inch across has a microphone diaphragm that is probably maybe 1/4 inch in size. Most studio mics have a diaphragm that is a bit bigger than the size of a quarter. There are limitations the smaller you get in the amount of sound the mic can accept. Technically you can use a speaker (which is just an inverted microphone) to record, but it will do a poor job as the diaphragm is so big that the amount of sound input required to make it vibrate enough to get a signal is too high.
If you take the cap off the Blue Yeti, the actual mic part looks like this.
cdn.recordinghacks.com/images/mic_extras/blue/yeti-capsules.jpg
Inside will also be the USB circuitry which is small as well as the headphone jack and wires to the gain knob, gain circuitboard, etc. Mostly inside the big hulking shell will be empty space I suspect. There isn't much else that could be inside.
