Why tiny JPEGs look different in Chrome

A while back, when chatting with a colleague over their computer, I noticed that a logo did not look exactly the same as it did on mine. It looked thinner on theirs and more faithful to the original image. It was rendered at 15px; here is an upscaled version. If you squint, or take a step back, the one from Chrome looks thicker. A bit weird, but swapping the image for an SVG fixed it. Still, I was curious: why was it rendering like this in the first place? I did some digging and found a nifty optimization that Chrome uses when rendering JPEGs at small scales. ↫ Guillaume Técher

I love it when people detail their discoveries like this.