In judo there’s a specific term for the one to whom a technique is being practiced on, the uke, and while their role is not often highlighted, it’s actually a pretty important one.
Jiu jitsu is one of those few sports where practice is heavily dependent on having another person. Sure, there are certain drills that can be done alone, but nothing really beats having another person in a gi on the mat with you. Not only that, but it’s highly preferable the person you are training with has some rudimentary knowledge of what you are trying to accomplish in drilling. You can get by with someone who may not have much of an idea- a white belt, your cousin while on some family trip (I personally have not done this…yet) but I think we can all agree that it’s preferable to have someone on the mat that knows what you are attempting to accomplish.
That in part has to do with giving you the appropriate reaction you need to complete the technique. While sounds a little like things are choreographed, it’s quite the opposite. Thankfully too, because otherwise I would be in all sorts of trouble. There are so many options and reactions to particular actions of the partner, that if you are focusing on one thing, the partner needs to provide the proper response to set up the technique. Say for instance I want to practice sweeping someone when they stand up, but my partner never stands up for me, and remains sitting on their knees. Sure, there are other things I can do, but that was not the purpose or intention of my drilling. There are more subtle examples of this that are often seen particularly when lower belts drill techniques- it doesn’t make anyone a “bad” jiu jitsu student, it’s just that understanding of just how deceptively important the role of the uke has yet to be realized.
I should also note that while a particular technique is being done to the uke, it’s definitely a time for them to learn as well, and the person should stay attentive, and not space out while a technique is being done to them (which we’ve all been guilty of doing, at least once or twice). The uke can not only to focus on how a sweep/submission/etc. should be done, but also how to get out of the situation. For pretty much all of jiu jitsu, there is an answer, a way to solve the puzzle that you are presented with. It just takes time and patience to figure it out, and time spent as a training partner can also be an opportunity to work out that puzzle. You may not solve it that day, but you could possibly be one step closer to the answer.
In short I guess appreciate your partner, and as the partner make the effort to stay focused. Providing an appropriate reaction for the other person is important, and can also be beneficial to both students’ jiu jitsu.