Add scratches to the bottom of the kids’ shoes and the bottom of the bots feet. Like deterioration… add some dirt, to the texture and some bumps to that area in particular.
Also, most machines like these are considered primitives machines, like ASIMO the robot from Honda… I mean, add some sort of serial name to it… in the texture like X2 - 9 some sort of robotic name… as part of the model “series” etc…
Just my 2 cents ok… Great job and continue the good work.
PS: Adding a female-bot to the composition will add a stronger feeling, in my case I would design her like on her knees in front of the little-bot (the red one)