An authorization question

[goPercy]

itest give authorization to 8576WBfDJ5FjQ92KN2jCZXFScJwrf3XWLrCQHMaiAF8b, while 8576WBfDJ5FjQ92KN2jCZXFScJwrf3XWLrCQHMaiAF8b is also iuser of activie key. when transaction packaged by Iwallet and send by iuser, publisher is shown as iuser. This is confusing. Is authorized user and pk equivalent in implementation? An unauthorized account becomes publisher, even if the signature key is consistent.

in testnet network_id 12D3KooWQwH8BTC4QMpTxm7u4Bj38ZdaCLSA1uJ4io3o1j8FCqYE

itest -> 8576WBfDJ5FjQ92KN2jCZXFScJwrf3XWLrCQHMaiAF8b 
iuser:  active_public_key : 8576WBfDJ5FjQ92KN2jCZXFScJwrf3XWLrCQHMaiAF8b

iwallet --account iuser call 'token.iost' 'transfer' '["iost","itest","ireceive","1.0","”]’
# hash: 9WKZi3qZqG13iw8wbGKx9X7eBteSYNhY19YvdoaeDggy

9WKZi3qZqG13iw8wbGKx9X7eBteSYNhY19YvdoaeDggy data :

...
"signers": [
        ],
        "publisher": "iuser",
        "referredTx": "",
        "amountLimit": [
...