FWIW, as a workaround, I manually resized ~/.cache/polly/previews/yfrog/nx36669873j to a width of 125 pixels and restarted polly.
FWIW, as a workaround, I manually resized ~/.cache/ polly/previews/ yfrog/nx3666987 3j to a width of 125 pixels and restarted polly.