The quote describes a humorous and whimsical observation where a person initially believes he has seen a rattlesnake, which is a dangerous creature. However, upon further inspection, he realizes that it is actually a representation of the middle of the upcoming week, a playful metaphor rather than a real snake. The scene highlights a blend of imagination and playful confusion.
The person expresses a lighthearted regret, wishing that the object or concept he perceives could speak, implying a desire for more clarity or communication. This reflects the whimsical tone of Lewis Carroll's work, emphasizing the playful and fantastical nature of his storytelling in Sylvie and Bruno.