From the image, it's difficult to tell if the animal is a true albino, as the whale's eye looks both pink and dark. But it is definitely an odd coloration for a whale that is normally all black with just some white coloring on its underside.
Albinism has been documented in 20 cetacean species, including humpback whales, sperm whales, pilot whales, and bottlenose dolphins. White (not necessarily true albinos) killer whales and southern right whales have also been documented.
Albinism is inherited, and occurs when both parents carry the recessive gene for the condition and the offspring receives both of the genes. Albinism causes a lack of melanin, the chemical which causes pigmentation, in the body.
Some animals do have pigment, but it is not expressed well, and these animals are white or lighter-colored than usual, but not true albinos. These animals have dark eyes, which may be the case with the animal that was photographed off Argentina. This condition is called leucism, and occurs when pigment is expressed only in certain regions of the body.