It looks like a Catholic Church. As a rule, the main difference between the Orthodox Church and the Catholic Church that the Orthodox Church does not accept the authority of the Bishop of Rome as the earthly leader of the Church. Father Richard Griffin was pastor of St. Ann's from 1972 to 1989, when he retired. Some folks stand for health reasons. Some folks stand for other reasons.
Some folks leave early all the time for other reasons.
Take Egypt Road from Phoenixville to Route 363. Turn left onto Rt. 363-N and proceed about one mile to an intersection of Rt. 363 and W. Main Street. It's a mystery.