Here is a quick demonstration of the kettlebell halo exercise. This is a great drill for opening up the shoulders if you don’t already have great flexibility in those ranges of motion. It can be used effectively as a warmup exercise.
That all being said I do not really use this exercise. Also I wouldn’t use it as an exercise by itself, it’s not something you’d really seek to do more weight or more reps in.
So if you feel you can use and benefit from the kettlebell halo exercise then go for it. If not, you can skip it and swing, snatch or press instead.