Doug, thanks getting me to think about how this effect would work on touch screen devices. I visited the page on an iPad. Tapping has the same effect as hovering. However, the effect worked everytime on a laptop, but not as evenly on the iPad.
Yeah, On my iPad (just went back and tried again) it sometimes works on tap. The other thing to consider is would a user know to tap? I wouldn’t know to do that; it’s not apparent that at least on that site, I could tap it. The changes also occur above the trigger so on a smaller screen the user may have scrolled past what has changed before triggering the change.