@JeremyECrawford @mikemearls Can the caster see Phantasmal Force? Can he move it or change it's behavior after casting?
— Dale Everett (@dalebert11) May 19, 2016
Only the target of phantasmal force can perceive it. And the caster doesn't get to change it after casting. #DnD https://t.co/GvDIjqWEvr
— Jeremy Crawford (@JeremyECrawford) May 27, 2016
Can the caster move it after casting?
Bold Rico
There’s no mention about movement except for the 10-foot cube area, my advice is that Phantasmal Force can’t move outside that area but if you want an official answer ask directly to Master Jeremy via twitter.