They love blanket criminalising anything done online...
Well, if they, a court, and a jury decide that "transmits the contents of such a publication electronically" inflates to "causes to be transmitted the contents of such a publication electronically" then viewing the video could be twisted into an offence under that section.
Much the same as the Communications Act 2003 allows a catch-all crime of "saying something offensive online" that can be invoked should you do or say something that enough people complain about on Twitter.