What it's all about? It looks like someone commented that they didn't think a band member was actually playing bass, and the band got upset.
I have no doubt someone who is playing would be upset at being accused of miming, and also that someone who is miming (but didn't want to be revealed as such) would be upset at being accused of miming.
I have no idea who the artist is, and whether they were actually playing or not, but if not, it wouldn't be the first time someone got on stage and mimed some or all of their performance.
I've got an old Roger Waters concert on DVD and although he certainly looks to be playing on most of it, there is a part where a bass is heard yet his hands are not playing it. Was he miming it all along? Was there a bassist offstage, or a track? Was it an edited spot in the video where they goofed up?
Miming used to be a big enough offense to get a Grammy revoked - now they will probably award one for it!
Having said all that, I did mime one time to a recording of myself playing while filming a TV commercial. It was a strange experience, if you have never done it - it's you playing that you hear, and you are playing the right part with your hands, so it was almost like you are playing it live - except you know you aren't!
If you bother to look at the video, it's obvious she's not only playing, but tearing it up. One thing is though, that the audio and video are not quite in synch. It's fairly obvious from the drums. This is pretty common for live videos that end up on Instagram, but it may throw some viewers off. That's giving them the benefit of the doubt, which they may not deserve.