Which sentence in the passage provides plot details that cannot be inferred from the images?
Little Women
by Louisa M. Alcott (adapted excerpt)

Laurie lay luxuriously swinging to and fro in his cozy hammock which was tied to a tree, one warm September afternoon, wondering what his neighbors were doing, but too lazy to go and find out. He was in one of his moods; for the day had been both unprofitable and unsatisfactory, and he was wishing he could live it over again. Staring up at the sky, he dreamed dreams of all sorts, when the sound of voices brought him out of his reverie. Looking through the meshes of the hammock, he saw Meg, Beth, Amy, and Jo, the March sisters coming out as if bound on some expedition.

Laurie wondered what the girls were doing, as he opened his sleepy eyes to take a good look, for there was something rather peculiar in the appearance of his neighbors. Each wore a large, flapping hat, a brown linen pouch slung over one shoulder and carried a long staff. Meg had a cushion, Jo a book, Beth a basket, and Amy a sketchbook. All walked quietly through the garden, out at the little back gate, and began to climb the hill that lay between the house and river.

He was disappointed because it looked like they were having a picnic and hadn't bothered to invite him. He decided to go up the hill as well. "Here's a landscape!" thought Laurie, glancing through the bushes, and looking wide-awake and good-natured already, when he reached the spot where they were sitting.

It was rather a pretty little picture; for the sisters sat together in the shady nook, with sun and shadow flickering over them, the aromatic wind lifting their hair and cooling their hot cheeks. Meg sat upon her cushion, sewing daintily looking as fresh and sweet as a rose, in her pink dress, among the green. Beth was sorting the cones that lay thick under the hemlock nearby, for she made pretty things of them. Amy was sketching a group of ferns, and Jo was knitting as she read aloud. The boy wondered if he should walk away as he did not want to force his presence on them. Since he was not paying attention to his whereabouts, he skipped back when a squirrel darted in front of him causing Beth to look up. She noticed the wistful face behind the birches and beckoned with a reassuring smile.