it is their symbol. and their secret history by watching this video.

Freemasonry is not the "mysterious" big deal people think it is. See the first site below.

Your image is a Gilbert and George piece: see the second site.

Freemasonry is a fraternity, the wiki site is pretty good for more info, as is www.masonicinfo.com.
Anyhoo... the depiction in this particular painting is not actually the Masonic Square and Compass, rather a Crucifix joined at various angles, which sooner or later does come close to mimicking the square and compass design. If this is on purpose or not or is meant to have some deeper meaning to the artist... who knows.

It's a coincidence. Not masonic.

Freemasonry is the world's oldest fraternity and largest philanthropy.

'Its symbol' isn't in the piece at all; it's a bunch of crucifixes joined at odd angles. No square & compasses present.