It looks sort of similar to this: https://chrome.google.com/webstore/detail/hacker-news-enhancement-s/bappiabcodbpphnojdiaddhnilfnjmpm https://chrome.google.co

It looks sort of similar to this: https://chrome.google.com/webstore/detail/hacker-news-enhancement-s/bappiabcodbpphnojdiaddhnilfnjmpm https://chrome.google.com/webstore/detail/hacker-news-enhanc... But maybe that extension spawned from whatever you had seen.