Actually, I am listening to the physical album right now, and on the track list on the back of the cover and inside the booklet it says "A Song for XX" with the roman letters. The shape is clearly XX and not ××. The album cover spine and the CD says "A Song for ××" though. I can only assume this means that either way is correct, it means the same thing (that is, A Song for "blank") and they only used ×× for stylistic reasons, as a logo of sorts.
wish they'd put the ×× and xx tags together... this one seems to be correct. @markprincegoan it's got nothing to do with multiplications, it's a mere placeholder that's not even supposed to be spoken when you say the album name, it's just pronounced "a song for". Writing normal exes like "XX" is wrong as they are letters and thus should have a pronounciation.