I don't think it's mean. The voice on the video seems really surprised. It seems more like they were amazed she'd try and then were really cool encouraging her to get it, which she did. I had a border collie when I was a kid and I remember that she seemed happiest when she accomplished something she'd tried to do.
It's not mean at all - I think it's totally cool and awesome! Border Collies are working dogs, and Reithe is spot-on. Working dogs need jobs and things to do and accomplish. I think Nissa could become a You Tube favorite - she's so beautiful.