Fürst Khevenhüller-Metsch am 8. Januar 1775:

However, the Emperor did not appear at all at the beginning and only attended rarely in order to convince his lady mother, so one hears, that his allowing of masks had been effected not out of consideration for himself but solely for the delectation of the public.

Joseph II only participated at court festivities out of a sense of duty, as Prince Khevenhüller-Metsch reported in his diary entry for 8 January 1775