The upper left-hand section depicts a brown-faced Moor, crown and collar. This element is not rare in European heraldry, and it is very frequent in the Bavarian tradition. It is called "caput ethiopicum" or "Moor of Freising."
As Ratzinger himself explained in his autobiography, this element has been included in the shields of the bishops of Freising for some 1,000 years. [Before becoming the Prefect of the CDF, Ratzinger was Archbishop of Munich-Freising.]
"I do not know its meaning. For me it is it is an expression of the universality of the Church, which knows no distinctions of race or class since all are one in Christ (Galatians 3:28)," he [Ratzinger] wrote.