This is a nice deal for Hong Kong Airport transit passengers. Through the end of the year, you can visit Hong Kong Disneyland for $230 HKD…(Approx $29.50 USD) vs $399 normally.
Main requirements appear to be a same-day stamp in your passport showing arrival in HKG, and a boarding pass for your later same day flight.
As you may or may not know, Cathay Pacific allows free stopovers in HKG on their tickets, both ways, so overseas visitors can try to schedule long layovers while they transit. For example, from Seoul to Sydney via CX, you could stop over in HKG on the way to Sydney, and visit Hong Kong Disneyland with the kids. This will also help break up an otherwise very long flight. On the return you can also set up a stopover in HKG for a few days and check out all of the other sights and goodies HKG has to offer.
For residents on transit, it you’ll have to enter with your passport rather than an HKID if you want to take advantage of this.