Complex sentence: One of the security staff allegedly asked a Hong Kong citizen to not take photos of the store and threatened to break his camera, implying that Hong Kongers cannot take photos of the store, but Mainland Chinese people could.
Split into simpler sentences: One of the security staff allegedly asked a Hong Kong citizen to not take photos of the store and threatened to break his camera. Allegedly claiming Hong Kongers cannot take photos of the store, but Mainland Chinese people could.