All chicks have spur buds. It's not an indication of gender. The chick in question is not a black sexlink, though. With that white skin on the bottoms of the feet, it's probably an Australorp. And with that red comb, it's definitely a cockerel.
Those are called spur buds, and all chicks have them. Some males never grow spurs, and some hens will. It's not a reliable way to assess gender.
At 6 to 8 weeks old, there is usually a noticeable difference in comb development in cockerels, and their coloring begins to get more patchy.