Walking through the Mass, these several sections of the GIRM give fairly particular details on concelebration.
GIRM 210-211 describe the procession and the reverencing of the altar.
For the Liturgy of the Word, the focus is on the Gospel Procession and the homily (212-213).
Gifts are prepare by the principal priest-celebrant. Concelebrants only approach the altar after the Prayer over the Offerings (215) …
… and stand around it, but in such a way that they do not obstruct the execution of the rites and that the sacred action may be seen clearly by the faithful. Nor should they obstruct the Deacon whenever he needs to approach the altar by reason of his ministry.
Visibility for the faithful is a prime consideration, as is the deacon’s ministry. The deacon, by the way, when not performing duties …
… stands back slightly, behind the concelebrating Priests standing around the principal celebrant.
Nothing unusual here, right? Comments? When we get to the Eucharistic Prayer tomorrow, there may be a surprise or two.
Catholic Sensibility 