Intel different CPU logo signfication

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)
 


But i one time found a laptop with this logo
http://

with a ref i5 2xxx (which means second generation) and the majority of the time all the other laptops which are with the same logo are i5-3xxx (3rd generation).How do explain this ?
Is there an equivalence logo=generation ?

Thanks a lot.
 


Because Sandy Bridge (2nd generation) and Ivy Bridge (3rd generation) were very similar (both used lga 1155, and some other things), as Ivy bridge was just a more refined version of Sandy bridge. Because they were so similar and essentially the same chip, they decided to use the same sticker as they were very similar. Therefore 2nd gen and 3rd gen processors share the same sticker because they are similar.

You can also see this in more recent processors. For example, 4th generation and 5th generation (Haswell and Broadwell) use the same sticker. This is because they are so similar. (both use lga 1150 motherboard, and again some other similar things)

So in reality, Intel just groups similar processor families together, and gives them the same sticker as they are essentially the same chip, and therefore don't need a completely differently designed sticker.