I think the "Miner Preference" is solely based from the fee/vbyte of your transaction, since it has a higher fee than the current highest fee, it's displayed as "high".
But it will still depend if a miner will pick-up your transaction.

The "Confidence" however, is based from their algorithm for the confidence factor: https://www.blockcypher.com/dev/bitcoin/#confidence-factor
That includes the fee rate, number of mempools that has the txn and other factors.

Can you click the "!" in the "confidence" to check how many nodes (that they see in average) have accepted your transaction?