What's the issue? These films are very complex chemistry, locked into unstable crystal structures at quench via fast cooling. Some are stable, some are weak, some are brittle, and they are microns thin. They lay over each other like potato chips. Some are stuck to the base material more strongly.
Energy of any form will release some of these structures from their temporary state. Rubbing, UV, solvents, heat, they'll all break the potato chips.
At some point they have to equilibrate. But if you are vibrating atoms with UV energy, some are going to move around.
No one ever mentions it on these discussions, but quench chemistry can be very exciting stuff.
