I think it's a simple, wonderful video showing the girl's feelings for her fish that has died. The parents are allowing her sweet expressions to be viewed and heard for others.
This is not a video to go nitpicking parenting skills (or lackof, if you so believe.)
Kids need to go through their grieving processes..possibly a little different than humans. If this is her way of showing it, there is nothing wrong, it's actually kind of cute. I don't think the mother was laughing because the "death" of the fish but possibly the way her daughter was handling it-- very maturuly, in my opionion.
As previously mentioned, the daughter never showed anger or frustration with her mother or father. The video was a cute tribute to Lucky. Nothing more.
I don't think this will be the next family to be on Dr. Phil or Jerry Springer.
"How bout a little black dress?"~hannahshule
"I have a penis, not a vagina." ~munkustrap178