My item rejected....why

My item rejected.
Here is preview video
What needs to change to make the project take?
Please share your opinions.

*looks like its lagging. bag of webplayer/my_pc or you did it? (slower speed may be) remove lags if you made it.

Thanks for the answer. I think that laggs because of the Web site, you can download a preview on your computer.

Are there some opinions?