I read GRRM's use of the word "smudge" as his way of saying "the answer"
almost as if he wrote the name of the POV chapter (with a quill and ink on parchment) in response to that person's question, then quickly 'smudged' the ink so as not to give a real answer.
i think he was being playful.
and also, because i couldn't resist:
https://asearchoficeandfire.com/ the word "smudge" six times in the first 5 books:
Catelyn VIII - AGOT
catelyn refers to the Direwolf of House Stark appearing on an approaching banner as "... a dark smudge in their center that could only be the direwolf..."
Sansa IV - ACOK
smoke rising from the southern shores of the blackwater rush "...its sooty fingers smudging out the stars."
Tyrion XIV - ACOK
Tyrion describes Ser Balon Swann's appearance as "...spattered with gore and smudged by smoke."
Sansa V - ASOS
upon inspecting her hair net after the Purple Wedding, sansa notices "There was a dark smudge in the silver socket where the stone had fallen out."
Cersei II - AFFC
reflecting on Lancel's appearance and his "mustache," while engaging physically with him, cersei notes "It looks like a smudge of dirt on his lip."
Daenerys V - ADWD
musing on the fate of the cities in her wake, Daenerys states "...yet it still seemed to her that the sky was darker to the southwest, smudged and hazy with the smoke of the Red City's passing."