Good vid! What video editing software are you using? It looks like it's a low resolution upload. That can happen in two places: 1. When you save the final cut the editor allows you to choose a saving resolution, sometimes stated as "where will you display the video", ie, FaceBook or YouTube, etc. The saved video will be resolution-optimized for that application. 2. During the upload YouTube allows you to select the resolution (I'm pretty sure, I haven't uploaded anything for a while).
When saving the file to my hard drive from the editor I ALWAYS choose the highest resolution available (it is determined by what file format you use and the resolution of the original media). When uploading I choose the "HD" (high def) resolution.
Given the pixelation, this video looks like it might have had a resolution drop in both stages
Good luck with your application!!!!