Have you ever purchased a product that says "store in a cool, dark place" or "keep away from sunlight"?
I keep my juices in a hard purple plastic cosmetic box, so they don't get exposed to additional light. I've purchased lots of juice, and if it is mixed at the time of order, most juice needs time for the flavor to optimize. I think Shanb's steeping video is spot-on. I basically do this with all my juices, and find it speeds up the aging process. I've seen a LOT of newbies post juice reviews after trying a new juice the day it arrives in the mail, or complain about a lack of flavor. There are some juices that are great right way, but most get much better with time. Which, unfortunately, you can't taste in the video.