Frankenstein water heater.
Is that contraption being used as a hydronic heating system by any chance? Small area of in floor radiant?
MMMMMM black iron for potable water …well it’s good enough for the gas line so why not! …right?!? 
Thats just so those that drink bottled, purified water still can get the required daily limit of minerals in just one swallow…lol
That’s the mosty amazing enema machine I’ve ever seen!
Whats with the wall control?
Where is the exhaust??
Is it electric?
It is gas (piping visible on left side of WH along with drip loop and controls at bottom), power vented (flue pipe visible on top slightly on right side of WH), control on wall is for circulation pump visible at right side bottom of WH, most likely used in part for hydronic heating system.
TPR valve is not properly installed.
And the problem is? lol
I really hope that is for a hydronic system.
Isn’t the gas line dirt leg supposed to be at the bottom of the long vertical run at the left there?