"polyn" is probably both misspelled and misstranslated. "Pyloni" in Finnish refers to a pillar that holds something up. The one who edited this probably thought that "pylon" would be the English equivalent for this expression as "pyloni" is clearly a loanword and thus originally not an originally Finnish word.
I guess eg. totem would work as good in this particular case. Here's a picture of the "polyn" on Mapillary https://www.mapillary.com/app/?pKey=177136870940831

