I'd log it, anytime you get in an aircraft and turn on the engine with the intent to get airborne it should be counted. It's not a matter of gaining "Experience" and you're not doing it for "Parker Pen Hours" or "BIC Hours", it's a matter of your logbook correctly reflecting what you've done for the day towards FnD hours.
As noted above as well, if you're in an Aircraft, taxi off and get delayed on the Tarmac for 2hrs are you just going to pretend you weren't out there for 2hrs? We all also include our taxi time in our logbooks so to now suddenly decide that time doesn't count seems a bit odd too. They don't specify what a "Flight" is so you need to think about what the spirit of your logbook is and the spirit of it is that it accurately records time you've spent in an aircraft in the duties of Flying as an accurate record of your experience and also in defence of your FnD hours you record should the relevant authority ever come knocking.