By covering taxes, I think the user is referring to the marketplace method of transfer.

1- The buyer of the funds lists an item with near no value on the steam marketplace for the amount (60 EUR)
2- The seller of the funds spends all the funds buying the 60 EUR item.
3- 60 EUR (minus 15% fees) get sent to the buyer of the funds, and the seller gets a near worthless item.

(Often, the seller provides the worthless item in a trade too)