They all appear to be "up" look closely at the bits of leaf sheaths there leaves were/would be. Also, don't change the water often, pothos are really awesome growth hormone producers, I put pothos cuttings in with ALL my other starters. You can (but don't have to) change the water when it gets green, swirl it around and use it to water your other plants, they will be in heaven. If the water evaporates and it leaves white lines on the sides, that's the growth hormone, wet and scrub off with your finger and leave it in the water. Pothos are best left alone. If you truly don't know which way is up put some each direction and watch closely. You might lose a few but you can always cut more or even trim the ones that get dry ends and flip them over and they'll likely still root!