You mean, after you “got further back”, on his body, maybe?
We normally start a horse just spraying as much or little as they tolerate without getting alarmed, then after a while we can spray more and more.
If we spray far enough that they notice it and start to worry, we sprayed too far those first few times.
We also are handling those new horses several times a day and grooming and teaching other, like about ropes swinging and moving things around and spraying a bit here and there and doing all kinds of things to see where they are in their handling and training.
The more we get to work with a new horses in all kinds of ways, the quicker they catch on what we do and why and that it is ok that we do most anything with them.
They trust us not to overface them and we try not to, find their holes and slowly work those into our program until they are confident there also.
For us, the most important for any new horse is to learn to listen to us and learn to cooperate.
What we do or not and how we go about it is all part of that master plan, more than getting a horse to do one or another thing only, like standing there to be sprayed in itself.