Referring to the graph, if real wages were to increase from W1 to W2 then the worker's substitution effect outweighs their income effect; therefore, they would be willing to increase their hours worked from L1 to L2.
Referring to the graph, if real wages were to increase from W1 to W2 then the worker will obtain a greater utility, due to their higher income. Therefore, they would be willing to increase their hours worked from L1 to L2.