Handbook of ROCOR Liturgical Practice:

In what way are the Holy Gifts on the Table of Oblation uncovered for the Bishop prior to the Great Entrance?

Prior to the Great Entrance (normally, during the series of Litanies the precede the Cherubic Hymn), the Priest who had served the Proskomedia goes to the Table of Oblation and partially uncovers the prepared gifts in the following way: the aer, the veil over the star, and the star itsef, are all removed and laid to the right side of the chalice — with the aer easily accessible, as the Bishop will place it upon the Deacon’s shoulder. The veil over the Chalice is not removed, but left in place.

Before the diskos is placed a small plate and spear for the Bishop’s commemorations. Next to these are placed the prosfora for the living and that for the dead, used in the Proskomedia and from which the Bishop will draw further particles, as well as an additional, new prosfora from which he will make additional commemorations. (Should more than one Bishop concelebrate, a new prosfora is provided for each.)