It's not a rendering artifact; it's an actual div moving with JS. <div id="cursor386" style="right: 643px; bottom: 346px;">(box glyph stripped out by HN)</

It's not a rendering artifact; it's an actual div moving with JS. <div id="cursor386" style="right: 643px; bottom: 346px;">(box glyph stripped out by HN)</div> Search for "cursor386" in bootstrap.min.js, there's a setInterval loop that moves it around. Appears to be from https://github.com/kristopolous/BOOTSTRA.386 https://github.com/kristopolous/BOOTSTRA.386