So basically, if the cloud edges are very sharp, the visible condensation is almost certainly liquid. But if you see fuzzy edges, it’s probably frozen ice particles. In this case, the wind up there is blowing pretty strongly. There’s probably a boundary layer where at one altitude, clouds are forming very close to another layer of air that has much higher wind speeds, so the bits of cloud that drift into the windy layer are being blown away from the rest of the cloud.

Also, frozen clouds tend to be higher in the atmosphere and either small things like in this picture, or just filled in “haze”.

Sometimes with a nice big thunderstorm, where the warm air rises very high into the atmosphere, sometimes the top will get high enough to cool and freeze, and as the top reaches layers that are often blowing stronger than lower layers, the top of the anvil will blow off and look fuzzy because it’s frozen. :)

Not a great example, but first one I saw that looks reasonable: https://i.imgur.com/k1LbGb3.png - the anvil looks a bit fuzzy because it’s frozen, but the lower parts look sharp because they are not frozen.

Also worth remembering/knowing that clouds are not so much… things… as they are areas of the atmosphere where the air can no longer support the amount of moisture, so the moisture becomes visible as it condenses. Which is how rain happens. Not sure what you might or might not know or be interested in, so feel free to poke me for the little more I know (I’m an amateur weather geek, most interested in hurricanes and severe weather like hail/tornadoes, so my knowledge is limited) :)