Everton also beat Manchester United last week, winning their opening two league games for the first time since 2007.
"It is great to come into a side that is in form," Mirallas told the Liverpool Echo.
"The team is playing very good football at the moment, and that reinforces the decision I made to come here.
"I knew I was coming to a great club, and the fact that we are playing so well at the moment is great."
The £5.3m signing from Olympiakos had a goal disallowed during his 20-minute cameo on Saturday and is expected to make his first start for the club, against Leyton Orient in the League Cup, tomorrow.