I can’t really see the trunk in the original photo in your post (the one with the purple light) but the trunk I can see in the forefront of the picture above will never grow taller than where it’s been pruned.

Once you prune a “leader” (single, main branch/trunk) it will not grow taller, but it will split into branches going sideways (or some other direction.)

Once you prune a plant, it’s like putting a dam in a stream. The water will find other ways to flow, but not where the dam has been placed.