Poor Steven putting his energy in singing the themesong well but his cast mates just did their own thing taking selfies, I guess on purpose to tease him. But still their behavior spoiled the whole singing performance for those in the audience who actually wanted to listen to Steven's live singing. (My intial feeling after watching 2 short video uploads, and before watching the below extended video, which was uploaded much later on youtube.)
eta: But after watching the extended video below, I've changed my mind. The group selfie when seen in its entirety was actually quite funny. lol! And Steven was so game too, and played along with their prank on him - their tease did show their easy camaraderie. lol! Anyway, kudos to Steven for singing so well despite the distraction.
Pls click on the original utube to show appreciation for such a superior video upload, and to watch this rare HD 1080 quality (and non shaky video too) in full screen. And download it for safekeeping in case it is deleted for some reason or the other.
utube uploader: chaumafei
Credit pix as labeled. Below pix are scaps from above video