Using an empty to control the Geometry nodes height.
Long winded tutorial, but he has all the parts to make a great looking burger. He uses geometry nodes for the seeds on the bun.
A use of geomery nodes that seems obvious. Great tutorial
He goes over a simple geometry nodes setup, and then a little about shading, and then compositing. Nice little animation with good advice about compositing to save time.
He goes over how to model the objects, and using the geometry nodes, and even has some images and blend files as examples. He tells us why to use the different nodes also very helpful. Great use of Geometry Nodes.