The fact that it was a french forum makes me think of Spectrum or MSX computer systems. Apple has never published an apple image that looked like that. It has always been a b/w or red plain apple or a rainbow apple. I'm not sure it was MS either. Amiga I could see.
That image does look familiar, but I can't for the life of me remember where I saw it and what it was advertising. It might have been in Compute! somewhere around 1983-84, it has the look of ads in US magazines of the time. (US ads often used pics either made using graphics workstations or other means that were always tons better than the advertised system could produce and had this "shine" effect applied so it would look like a photo taken off a TV.)