Inspired by the top image, where it’s apparent that opening the envelope containing the installation media is promised to void the warranty on the software being sold. Is that a valid loophole? Warranties can already expire, meaning they are nullified by a predetermined amount of time presumably including normal usage within that time. There are also shrinkwrap licenses, so called because breaching the shrinkwrapping on the package the install media is sold in signifies your acceptance of the terms of the license. Is the iteration of the concept in the image above valid?
Here are a few relevant court cases, courtesy of Wikipedia:
I looked at the image and I have to believe that some bozo put the wrong sticker on the envelope. Generally you see stickers like that on hardware, like disk drives. The stickers on software envelopes say, as you mention, that opening the package implies consent to the licensing terms.
It would be just stupid to void a warranty if the product is used as intended…
Considering that the link is to a TDWTF article, I would have to agree with CookingWithGas that “stupid mistake” is the most likely explanation.