For an example with my newly submitted YouTube video in https://videosift.com/video/Animaniacs-Chicken-Boo-Segments:

1. Even though VS made an embed code with my copied and pasted http://www.youtube.com/playlist?list=PLMZYxQGS-jB8aQ_A72FYCpd9nDZAc20sz URL, it didn't show the embedded video. So I had to use YouTube's shared embed code to make it show up correctly in VS.

2. *findthumb doesn't find any thumbnails as Siftbot says.