Besides the date, the only information we have for this one is A.O.H. Fancy dress, group. I'm taking A.O.H. to be Ancient Order of Hibernians? However, fancy dress doesn't describe the uniformity of costume, so I think this is an amateur dramatics cast in full regalia - Pirates of Penzance perhaps?
Thanks to desmondg47, we now know that this photo was taken at the rear of City Hall/Theatre Royal on The Mall, Waterford.