The one on the left looks normal. The one on the right looks like you ran an edge-directed upscaler on it. Those things have distinct artifacts, and sometimes

The one on the left looks normal. The one on the right looks like you ran an edge-directed upscaler on it. Those things have distinct artifacts, and sometimes it looks like all curves turn into snakes. Or it can make new diagonal curves out of random noise. Not knocking edge-directed upscalers though, they can work in real time and are very good for line-art graphics. You can even inject them into games that have never had that feature before.