High pass is the opposite of low pass, which means it will magnify details. When the effect of this tool is applied to the fullest, you will see the picture lose saturation and become almost like a drawing. In fact, that is the end effect of a high pass filter: underlying all details. To make it work in practice you will probably want to reduce its effect by combining it with an opacity layer.
The high pass filter will Increase details toward the edges (and increase lines width as in a drawing), using the soft light blend mode in combination with a high pass filter will temper the effect so that it becomes more natural and blends into the image, without it the picture would just lose colors and become gray, like pen strokes.
When to use: this type of filter works very well with hairs and everything that looks furry, and when you want to brighten the image in addition to a light blend mode.
The high pass filter is also used to transform an image into a drawing like, without AI tools assistance.