Last year there was one in the Christmas village/display in Chater Park/Statue Square. You had to bring your own camera, but they took your picture for free.
Haven't been this year, hoping to head that way tomorrow.
i don't think there's one in statue square. in fact, there's not much xmas decor at statue square this year, heard it's some disagreement between the landlords, by the time they could agree on sth, it was too late.