I've just been using some UI templates and in some cases, the 'bounding box' for transformations is huge compared to the actual object in it. For example, I have a little 'back arrow' shape probably 40px wide, but the transformation box is more than 1000 wide and high. How do I 'clip' or crop it (for want of a better term). It may be called fitting the frame to the content.
The bounding box is sized to fit the layer contents and any associated layer mask. You can't "clip" the bounding box. If you want a smaller bounding box, you need to remove stray pixels from the layer and possibly apply any associated layer mask.