Just like most services there is a timeout period to receive confirmed funds, for this payment it was 15 hours. The buyer either waited a long time to send and/or didn't include enough TX fee so the funds weren't confirmed until 4-5 hours after timeout.
I note that they're quite happy to accept that amount as a payment and then forward it on to a merchant.
Generally merchants accepting micropayments use To Balance mode so it goes to their CoinPayments Wallet, that way it is a ledger entry versus being sent on-blockchain with a TX fee.