Shutterstock's Enhanced License allows:
Unlimited physical print runs
Unlimited impressions of Out of Home advertising
No budget restrictions on video/multi-media Productions
Use on merchandise for sale
Basically, the Enhanced License offers much more flexibility.
By contrast, the Standard License does not allow use of images on merchandise. It also limits print runs to 500,000 copies. This includes anything printed in physical form as part of product packaging and labeling, letterhead and business cards, point of sale advertising, billboards, CD and cover art, or in the advertising and copy of tangible media, including magazines, newspapers, and books provided.