Whittaker's is a well-known and very well-loved chocolate maker in NZ.
They make really good chocolate, and they come out with different and innovative ideas from time to time. Just to give UK people, who probably won't be at all familiar with them, some background.
This particular idea is a take on gender reveal parties - so you buy the block, not knowing whether you will get a pink or blue bar. You don't choose pink or blue.
Funds from sales go to Plunket, NZ's biggest children's charity.
I think they may have bitten off more than they can chew with this one though (no pun intended). Now that the rainbow, non-binary, gender fluids have got wind of it.