[Please provide the exact location of the extract in the novel to easier help you.]
Since I was not sure of the exact location of the extract you refer to, and because you are examining Lennie's physical description in the novel (an introductory exercise), I have examined the beginning of the story.
In John Steinbeck's Of Mice and Men, we receive three descriptions of Lennie that provide clues for his characterization. In Chapter One, when George and Lennie first appear, George is described as small and alert, while his companion is described as large and lumbering, "dragging his feet a little the way a bear drags its paws."
When they reach the pool of water, George hesitates, but Lennie without thought, drops to his knees and begins to drink, "...with long gulps, snorting into the water like a horse." Lennie's hands are referred to as paws again, and then later in the chapter, when George demands the dead mouse, Steinbeck writes...
Slowly, like a terrier who doesn't want to bring a ball to its master, Lennie approached, drew back, and approached again.
From these descriptions we learn that Lennie is a lumbering, giant of a man who is physically awkward (as he draws his hands like bear paws), has limited "social skills" (gulping water and snorting like a horse), who is also stubborn (like a terrier, when he resists giving the dead mouse to George).