Snapchat videos are only viewable publicly as stories for 24 hours. In order to 'view it' you would need to know her snapchat handle. In order to save one you would need a special app/hack/software on your phone to do so.
I saw no passenger face at all in that video. Just 2 or 3 flight attendants having fun on snapchat.
There's a lot of unanswered questions here. How did "you" or at least the "youtube account" manage to save her snapchat video to upload it to youtube?