Thanks.that does look like a minor swim bladder problem. For goldies, I'd recommend not feeding them for a few days to see if that helps the problem. Monitor for regular pooping because constipation is the most common cause. If fasting for a few days does not help, then try adding some pre dissolved (PURE) Epsom Salts to the water. 1 tsb per gallon is ideal, but that can be raised to 3 tsb per gallon over time.
**If the fasting for a few days does nothing, you can try and give them a few thawed, de shelled peas. This will help move things along as well as the Epsom salts.
Has this goldfish had swim bladder problems in the past? It could be that the cause of the floatyness is actually a deformity in the swim bladder. This is thanks to their un naturally short, rounded bodies. I don't think there is any sort of treatment for a physical deformity.
All of your other goldfish look amazing by the way! Great colors and variety I can only imagine the loveliness of the group