When William and Dorothy Wordsworth arrive at Coleridge's cottage and they go in search of Sarah Coleridge, the baby, Hartley is sitting on Sarah's lap with bare feet. When Sam introduces the Wordsworths to the baby a second later, he is wearing red boots/booties.
As they are rolling around from the effects of "Thornapple", the shot of the clouds rolling by show the quick streak of the exhaust of a jet airplane zipping from bottom to top of the picture.