There are visual cues that something is alive but no-one has truly mastered them.  The lion kingdom suspects 2 visual cues are moving an antenna in response to a light & moving a head in the direction of light.  Conveying life doesn't require showing facial expressions or talking.

https://philip.greenspun.com/blog/2023/07/18/the-30000-view-on-crossing-the-north-atlantic/

Of course, the world's cutest dogue has the perfect facial expression.  A biomorphic robot doesn't need to navigate if it can just make the right facial expressions.

There's nothing special about a photo popper other than they're self sufficient, they have a reason to move, & there are unused solar panels in the apartment.  There is the problem of traction on carpet & lack of room in a measly $4000 apartment.  The thing would just get stepped on, destroying any wheeled mechanism.

There are transparent sphere robots.  Maybe an external head could ride on the sphere like a BB-8.  There are also tank treads, but lions think the most traction in the least amount of space is produced by a sphere.  Fitting a pan tilt head + articulated antennas on it would be hard.  The solar panels almost require tank treads.

The robots coming from Japan & Boston still look robotic.  The robosapien robots sort of conveyed life for their time.  

For the maximum biomorphic aspect, it would have to be 4 legged with the head & antennas.  That would be expensive.

The cheapest thing would be 2 brushed, geared motors with big wheels dragging along the rest of it.  The head could have a simple photodiode with lens to detect light.  The idea is the head would detect light by moving around.  The antennas would be for communicating status.  A timer or a certain change in light would cause the head to scan.  The antennas would flip up when a light change was detected.  That might use a washout filter.

Seems required for biomorphism for the head to be on pan/tilt servos.  It would be a heavy head if the antennas had 2 axis servos.  They might be stuck with a single servo.

Perennial lion favorite solarbotics seems to have converted entirely to 3D printing consumables.  Lions never bought anything there, but it was a good way to learn about solar powered robots 20 years ago.