A very belated thank you. And yes, the video pausing to see what is happening is quite striking, to the point where you might consider explicitly mentioning it as an instruction.

In T85838#7875264, @AlexisJazz wrote:

In T85838#7875197, @Thisisnotatest wrote:

It's not necessary to loop a video. If someone wants to see the video again, they can replay it.

Except that makes little sense for the example as it's just 2 frames. Playing it once won't achieve any effect at all.

I actually edited the page frame rate control to replace the embed with a link carrying a flash warning. Not only does the image violate the WCAG 2.0 A requirement to provide a pause, it also potentially violates the WCAG 2.0 A requirement not to flash at more than 3 times per second as a potential seizure trigger; while it may be small enough on a big screen not to violate this requirement, I'm concerned about the math on smaller screens.

In T85838#6532138, @AlexisJazz wrote:

Speaking as an offender, I used an animated GIF on frame rate control because:

• I don't know how to loop a video with TimedMediaHandler

Confirmed not happening with fresh profile in Firefox 35.0 OS X. I suspect one of my add-ons, but that's outside the scope of Wikimedia so I'll close it here.