Even though it’s summer, at some parts of Antarctica it’s still cold enough for new sea ice to form. Due to its higher salinity sea water only freezes at -1.8ºC. When it freezes, small ice crystals will form, clinging together, forming frazil ice. When these small clumps of ice lock together, they form larger pieces, as van be seen on the picture above: grease ice. The next stage normally is to form round plates, with a diameter of up to 3 meter. This is called pancake ice. And finally these pancakes will stick together and new pack ice is formed.
I don’t think this grease ice will have reached that stage as the next day the wind picked up quite a bit, breaking up all newly formed ice.