Sorry a bit unclear:

i mean in time

733862 has 27/04/2022 - 20:24:30 UTC

733863 has 27/04/2022 - 20:22:44 UTC

thank you for your explanation

It doesn't necessarily have to be used as extranonce to be different than the real time. Timestamps are set by the individual computer (there is no universal clock in some centralized server that we use) and all computer times all around the world don't have the same time. Sometimes the clock is just wrong. One could be ahead and another behind hence causing such time differences in block headers.

This isn't correct. The timestamp is unrelated to the verification of the blocks, which is what I assume you mean by the "computing process". As I've explained above, there is a range of a few hours the timestamp can fall within and still be valid, and there is nothing stopping later blocks being stamped as earlier than preceding blocks.

The timestamps also say nothing about the order in which the blocks were mined. Each subsequent block (based on block height) builds on the previous block. It's not possible for a block to be mined earlier but then not broadcast until after other blocks have been found.

Even if the pools do that, they still have to first set the timestamp and them mine one block at a time which means the timestamp of each mined block becomes immutable and is still following the same consensus rules as any other block that is broadcast normally.