So for context Braxia has a central AI that controls its systems like the vaeda but unlike vaeda where the AI is a separate entity that can plug into vaeda, Braxia is the AI and the machine is its body.

but when talking to Thomas he projects himself as this holographic avatar that only Thomas can see due to their connection but others can see him if he decides to let them

TL.DR braxia is conscious and is his own character and this is what he looks like when thomas speaks to him