Is this safe? I big mountain of steak, already heated.

Depends what temp the meat is kept at and for how long.

 

I would suspect it's fine. But i agree with French Fries, depends how long it stays and what the temp is.

 

As the others said depending on the temp and sitting time it could be safe, but that doesn't mean it's going to taste good.

 

As it sits on the hot griddle in a stacked pile, it is still cooking and probably is no longer toward the rare side. This is ok as long as more is not cooked and put on top. If all used within say 2 hours all should be well. 

 

You are a brave man if you eat that meat....

I'm just too much of a 'fearty cat' to do such a thing!