It's just the logo design from each different generation.
For example, the first link you showed was the logo of a 4th generation Intel core i5 processor (i5 4670K)
The second link is to a Previous generation (also known as 1st generation) Intel core i5 processor (i5 760)
The third is a link to a 3rd generation Intel core i3 processor (ivy bridge) an example of this one is an Intel core i5 processor (i5 3570k)
The fourth is a link to a Previous generation Intel core i7 processor (i7 920)
The stickers tell you which generation your CPU is from.
Here's some more info on this: http://www.pcmicronenterprises.net/intel-generations-of-processor/
As for the different previous generation Intel core stickers, the fourth link you sent was the original badge for the Core i7 line (when they just announced the i7), the second link you sent was the sticker of the second wave of the Intel Core I7 parts, after the first one was out for a while.For this they changed the sticker to the one in the second link. (Similar to Intel first releasing the I7 4770K, then the I7 4790K)