Roy wondered what would happen if the second target for the device weren't even a person. Would it work? Would it do anything? Would it do something weird and unpredictable? Deep down, Roy was a curious experimenter (just like his alternate doppelganger from the other reality). He looked around for an inanimate object for the second target.
From what he saw there were three options. There was an old vacuum cleaners out in the hall left by one of the janitors. Another option was Miguel's action figure being clutched tightly by the child. The third option he saw was Elena's doll, which was currently being brushed by the cute child.
Roy figured he could choice one of those, but he could tell the family was leaving soon so he had to act fast. After another few seconds of thought he selected the object and pushed the button on the right.