A lot of SM figures are motivated by money, aren't they?
They are trying to build enough followers to monetise it. After all, it's a lot of work to be constantly producing content. Even if the content is engaging in a viral trend.
DD does some of that for fun, which means she has about 1,000 subscribers, some are friends, but mostly it seems to be people who are trying to build their own numbers and the etiquette seems to be that if someone subscribes to you, you subscribe to them. They aren't people who genuinely follow you because you are doing something interesting! Because following a viral trend isn't very interesting unless you add something new and unique.
That's fine for DD because she isn't trying to build a brand or subscribers, her intended audience is her friends and she does it when she feels like it and has time. She posts something most weeks, but that's just her generation's way of chatting with friends.
Are H&M chatting with friends with this video? They don't seem to be the right fit.