As I said some posts above, I think that the message is not hiding another one but just showing the ability to communicate and maybe providing a code to decipher following messages. So I started speculating about what this code could be.
I realized that one may unfold the circle along its circumference and
interpret each quadrant as a different symbol.
In that case, the lower left quadrant corresponds to our Pi symbol.
The depiction of Pi both as a number (3.142) and as a symbol doesn't seem a coincidence to me. There are also some works in the sci-fi literature where Pi was the key to decipher some alien artifacts:
And, most notably,
Notice too that the 4 quadrant symbol is also the usual symbol for
Earth. Coincidence?
If the inverted T symbol is interpreted as usual in
logic, the = symbol is also interpreted with its usual meaning, and we suppose the symbol in the top right quadrant to be a representation of 3, one may read Pi=3 False by starting in the lower left quadrant and reading clockwise.
Food for thoughts.