Final answer:
Stevenson uses foreshadowing and metaphor to make Dr. Jekyll's first appearance seem important.
Step-by-step explanation:
In this passage from Chapter 3 of The Strange Case of Dr. Jekyll and Mr. Hyde, Robert Louis Stevenson uses various writing techniques and literary devices to make the first appearance of Dr. Jekyll seem important. One of these techniques is foreshadowing. The mention of this being a 'private matter' hints at a secret that will later be revealed. Another technique is metaphor. Describing Dr. Jekyll as a 'large, smooth-faced man of fifty' creates a visual image and emphasizes his physical presence. Through these techniques, Stevenson creates an aura of significance around Dr. Jekyll's first appearance.