I have been considering taking up Arcanist to become a Summoner for the awesome summons. In case anyone other than me needed a bit of reassurance about whether the tiny little summons we've seen thus far are the norm. I found  a reddit with datamined images.
 Take it with a grain of salt as this isn't confirmed but in one shot there is a Summoner accompanied by a not so little Beastie.
http://imgur.com/a/DPD65
 Take it with a grain of salt as this isn't confirmed but in one shot there is a Summoner accompanied by a not so little Beastie.
http://imgur.com/a/DPD65