The stream is not bent, yes, but the end of the hose is at a different position for each frame. The hose is taped to the speaker cone.

As I wrote above, this was discussed some time ago (2013):
http://www.pgmusic.com/forums/ubbthreads.php?ubb=showflat&Number=198244&page=2

Here are more evidence showing videos:
https://www.youtube.com/watch?v=UOfAmsQvgg4
https://www.youtube.com/watch?v=_ytAq9sOXMo
https://www.youtube.com/watch?v=H11YqPI25Wg
https://www.youtube.com/watch?v=3y4EaJrJP9w


Desktop; i7-2600k, 8 GB mem., Win 10 Pro, BIAB 2017; RB 2017 - latest build
Laptop: i5-2410M, 4 GB mem, Win 10 Pro, BIAB 2017; RB 2017 - latest build