Task #1: Adjusting the pixel dimensions of an image possibly off by 1px

[astephan1]

Howdy. This probably isn't a big deal, but I found it slightly odd so I figured I'd mention it. The image at the URL below was originally uploaded at 600px square. When Theo's Little Bot performed a resizing it became 316 x 315. This seems a bit odd to me. Shouldn't it be either 316 x 316 or 315 x 315?

The image URL: https://en.wikipedia.org/wiki/File:John_Williams_Changes_Album.jpg