As judges we are there to observe and make comments and not there to deliver lessons. Certainly in the time available and in the space available it's difficult to impart meaningful advice. In its place we restrict ourselves to comments which relate to the directives and the requirements of the movements.
Here are some typical comments (
more available Master Dressage 2nd Edition )
Needs more suppleness – this could mean you need to demonstrate more suppleness by improving your accuracy or fluidity. It could also mean that the horse is not yet supple enough for the movement being asked of it, perhaps the horse does not smoothly change bend, or perhaps does not show enough bend.
Inconsistent to contact – this could mean several things. It could mean that your horse does not maintain his head carriage steady, or that he is moving his head around playing with the contact, for instance a horse that flicks its head forward and back. Of all the different ways a horse could be inconsistent to the contact, they all mean one basic thing; that the horse has not yet learn to reach toward the contact over his back and over his neck in a consistent way.
Against hand – this normally occurs in downward transitions, but can be seen in upward transitions. It could mean the horse is throwing his head against the hand upwards, or that the horse is leaning against the riders hand.
Lacking/Losing Rhythm – this is used when referring to a changing tempo, and also when the rhythm of the pace is breaking up. For instance if the walk becomes tense, or the horse begins anticipating canter. Some judges are more discerning and use the words tempo/rhythm more correctly.