This is balance - something (a 128 GB thumb drive) in the foreground, and an old 6 KB core in the background.
Here the sextant is being framed by a table of figures used to reduce the sextant's reading to a position.
This is both framing (Marybeth's shoulder) and balance - the modern e-reader and old books at a distance.
More framing - the plane is framed by the clamp.
leading line - the Bubinga board leads us to the plane.
Leading lines and layering - the probe leads lead us to the scope, and other test equipment is in the background.