Two Reasons Why This Is Not The Original Earth-2 First we see a picture of Batman on the wall. This picture of Batman has a yellow oval around the bat on his chest. The real Earth-2 Batman NEVER EVER had this yellow oval.
Second, we see the Spectre. The real Earth-2 Spectre left the real Earth-2 to live on Earth-1. There were NEVER 2 Spectres, only a single one. If this earth we see in the book was the real Earth-2, there should be NO Spectre on it, since he left it in the 1960's (real world time) and he never returned. He remained on Earth-1.
The photo on the wall of the original JSA membership includes Wonder Woman, who was not a founding member.