To illustrate Nicolas Steno's Law of Superposition, you would select an observation involving a sequence of sedimentary rock layers. According to this law, in an undisturbed sequence of sedimentary rocks, the oldest layers are at the bottom, and the younger layers are at the top.
For example, an observation showing a cliff face or a road cut that displays multiple horizontal layers of sedimentary rock, where you can clearly see that the bottom layer is older than the layers above it, would effectively illustrate Steno's Law of Superposition.
If you have specific scenarios or features in mind, please share them for a more tailored example!