Quick question: different zero in DID and NFT

With decoding the solution, I found the representation of zero in DID singleton_launcher and NFT’s is different:
DID: 0x0000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000
NFT: ()

I want to know the differences, or it’s just because the decoder work differently according to some condition?

EDIT: add some information:
From source code, I found they are different:

DID code:

        genesis_launcher_solution = Program.to([did_puzzle_hash, amount, bytes(0x80)])

NFT code:

        genesis_launcher_solution = Program.to([eve_fullpuz.get_tree_hash(), amount, []])

But I still not understand why they are different.