Just found this today that YouTube is now providing an ultra low bandwidth video quality mode. It’s probably for those situations that user want to just hear the music or having a small screen. The video quality is not good, but it’s worth a try :p
Users are not able to choose resolutions for their video(s). YouTube automatically enables the highest available resolution according to copyright and the uploaded video’s details; for example you upload a music video contains copyrighted materials, then YouTube will decide to remove your video or limit the resolution of it to protect author’s rights.
Please manually change the video quality to try.