The reader might become more attached to Buck, and if it was told from the trainer's point of view, it might change the reader's opinon on Buck, and make it more on the trainer's side.
Friar Lawrence was the man in romeo and juliet that had a secret wedding for them to get married
<span>When the Scarlet Ibis drops exhausted from the tree</span>
Well you use context clues, (by the way this is called finding it indirectly :P), and visualize what the theme and message the author's tryna get across, like for example in The Lorax; They don't DIRECTLY state it, but based on the story sequence and structure, you could conclude that the central idea is to take care of Earth, and appreciate the things that comes out of it, because they may not be there for granted if we continue to pollute. c: