Its really the whole thing. It looks like a summer outfit dressed up for winter. You've got a sweater-looking shirt, casual boots, and then pair them with what look like jorts. Its like dad-casual gone awry.
If you were going to pair the shirt and boots you'd need casual pents. If you were going to try the jorts, you'd need a much more casual looking shirt - maybe a short sleeve polo, and a pair of casual sneakers or flip flops.