You asked if this was a diocesan "ritual"? It has occurred at three parishes. Twice we were to bless comnunicants,a couple of other thimes,the newly baptized and once,last week,in fact,it was to bless all of those parishioners celebrating their anniversaries in June. Several mother's days have occasioned this "blessing" too. This has been going on here for many years and as I said in my previous post,from the back of the church,it looks for all the world like a Hitler Youth Rally.
Yes, I have seen pictures of similar blessings on other web sites. That was my first impression too!
It takes strength of character and the courage of your convictions, but if I were you, I would pull the pastor aside one Sunday after mass and ask him where these blessings are to be found in the GIRM. You have nothing to lose and plenty to gain.