My experience with 6 minute long vids is limited to um... three vids, one never completed, but based on that, I'd say that the problem with subtlety in long vids is that if you're trying to do something in longform, you probably have more to say than you do in a short vid, so the ratio of content to time is about the same and you still don't have room for subtlety if you want it to be clear to your audience.

And ugh, I hate comments like that. I always say that it's important when operating in online fandom to remind yourself periodically that some fraction of online fandom is twelve years old.