The top bar of the cross represents the mockery Christ received as He was taunted as “King of the Jews.” An Eastern Orthodox Christian Prayer for Friday explains the meaning of the footstool of the cross being slanted toward heaven and the repented thief on His right.
In the midst, between two thieves, was Your Cross found as the balance-beam of righteousness;
For while one was led down to hell by the burden of his blaspheming,
The other was lightened of his sins unto the knowledge of things divine.
O Christ God glory to You