Have a look at how some of the panels fit together (look near the doors and by the ceiling). There's a white rubber-like tape/seal along many edges, and in many cases it's been stretched to the point where it hangs down or is misshapen. Possibly as the panels have been removed and not fitted back on properly.
You'll see it on almost all the trains, so someone clearly didn't design things that well. After all, the trains will need maintenance so surely you'd make sure panels could come off and go back on securely (and the right way around).