Wow. That’s heartbreaking. It’s such a scarring image to see someone you look up to degraded and humiliated like that.

One thing I’d say is that the sentence He’s going to a place called Vietnam, my mom is inconsolable. should be fixed (I’m not sure if this is what the posh grammar people would call a fragment?) Basically the comma should be replaced with a full stop of a semi colon.
Your descriptions seem to grow up with the character. The first of a mix of the Jolly Green Giant and Santa is very four-year-old… and it’s almost like by seeing Uncle Robert so battered, it has forced the protagonist to grown beyond his years with the shock of it. The description in that last paragraph is so vivid and beautifully hideous.

graphic, intense, and yet simple words do so much for this piece.

An electric description. All to realistic. xtremely well done.

This one broke my heart. But while the exact imagery was startling and not what I expected, I did know where this was going.

Still, very well done.