After watching these videos, and thinking about diamagnetic levitation, I suddenly realized a certain phenomenon that is experienced with electronic devices and magnets. In particular, what happens to magnetic storage devices like hard drives when a powerful magnet is introduced to it?
It is DESTROYED!!!
Hard drives like the ones in that Lenovo Thinkpad in the ISS video are susceptible to this. If you introduced a high-powered magnet, such as one in an MRI or perhaps one that could levitate a human, to the laptop, it would surely crash! That laptop looked fully functional in the video.
It seems like you can rule out diamagnetic levitation as an explanation for their apparent weightlessness.