that nonstandard address should appear on bitcoin explorers as the plain text term "non-standard" but the transaction author knew that mempool.space has a naive/buggy address parser and exploited that to make the address look like a valid-but-incredibly-short segwit address
"bc1pfeessrawgf" is the correct address rendering for this output, since it is a valid segwit v1 witness program, even though the combination of witness version & program length does not correspond to any defined spending rules.
(although the 2-byte 0x4e73 output script does match a proposal for ephemeral outputs).
Fun fact: undefined segwit outputs like this are completely standard to create, and only non-standard to spend.
However, this transaction did prompt us to fix a bug on mempool.space that calculated the dust limit incorrectly for this kind of output, which caused the transaction to be falsely labeled as non-standard for a short time.
0x4e73output script does match a proposal for ephemeral outputs).