Dislocations in motion

I'm still working on figuring out exactly what's going on in this video. I know the image was taken with a transmission electron microscope and that the sample must have been only a few atoms thick - thinner than a wavelength of light. The squiggly, darker lines show where the crystal dislocations are moving through the material because of some stress - warming, perhaps - being applied to the sample.

I'm struggling to find out any more than that, but I'm stunned to actually see the dislocations that we discuss in our metals unit, things that we can feel on a macroscopic level when we work metal - cold work it, anneal it, temper it, quench it, roll it, draw it.

If anybody knows more about this, feel free to explain.