Let's see a second example.

Let's look again at Figure 2. There are 300 particles of compound distributed between 100 mL each of solvents 1 and 2.

When you double the volume of solvent2 (i.e., 200 mL of solvent2 and 100 mL of solvent1),
the 300 particles of compound distribute as shown:

Compare the results observed in Figures 2 and 3.

Solvent2 is the extraction solvent, i.e., the solvent used to remove (extract) compound from solvent1.
In Figure 2, 200 of the possible 300 particles are extracted into solvent2,
whereas in Figure 3, 240 of the possible 300 particles are extracted into solvent2.

If you use a larger amount of extraction solvent, more solute is extracted.

But -- what happens if you extract twice with 100 mL of solvent2 ?

In this case, the amount of extraction solvent is the same volume as was used in Figure 3, but the total volume is divided into two portions and you extract with each.