Most Helpful Guy
You can't do anything to make their day better if they are in the zone where they are going to self harm.
I have a friend that cuts and she can be happy and having a laugh but then cuts herself.
All you can do for your friends, like me with my friend, is be there when they need you.
Please don't send them a video or try to say something to make them feel better. If they are in the zone they will think you are being patronising and that could cause to self harm again.
Sorry I can't help more than that but it's how it is.