Someone correct me if I’m wrong but I think it counts popularity of songs based on worldwide social media mentions/views.
T-ara does really well in that section because they’re pretty huge in China and the chart includes Chinese sites like Yinyuetai.
But I’m always confused about this because there’s quite a lot of groups that do well on YouTube and other social media sites that only manage to chart on this for like 1 week. So I have no idea what the criteria for it is.