Sunday's historic Solemn Pontifical Mass at the altar of the Chair in St. Peter's Basilica with the participation of no less than four Cardinals of the Holy Roman Church is also being reported in the 16/17 May edition of the Osservatore Romano, the "semi-official" newspaper of the Holy See. On p. 6 is the following article (NLM translation) including a photograph:
At the altar of the Chair of the Vatican Basilica
Mass in the extraordinary form of the Roman Rite
On Sunday morning, 15 May, concluding the third conference on the motu proprio Summorum Pontificum, Mass in the extraordinary form of the Roman Rite was celebrated in the Vatican basilica. At the altar of the Chair it was celebrated by Cardinal Walter Brandmüller, in the presence of three Cardinals - William Joseph Levada, president of the Pontifical Commission Ecclesia Dei, Franc Rodé and Domenico Bartolucci, who directed the final chants - and some bishops and prelates of the Roman Curia.
The Photo Service of the Osservatore Romano carries a large selection of photographs. Here are some samples (click to enlarge):