I always thought that this was a feature for the OS X developers to 'debug' their transitions. You can do fun stuff with it though, e.g.:

- Open a terminal, enter "killall Dock", don't press return yet.

- Surf to HackerNews in your favorite webbrowser ;).

- Hold shift and minimize the window.

- Very quickly switch to the terminal and press return.

Now your browser is stuck somewhere halfway the transition. The nice thing is that you can still use your web browser in its deformed state.

You can fix your web browser by (really) minimizing and then maximizing it.