Posting a picture of a pig en route to the slaughterhouse, Silverstone quoted musician Sir Paul McCartney's famous line: "If slaughterhouses had glass walls, everyone would be a vegetarian."
The post received largely positive - thought some mixed - responses, with one commentator saying: "If slaughterhouses had glass walls you still wouldn't see anything from blood..."
Silverstone has been a vegan for many years, after trying vegetarianism on and off in her youth. She often advocates for veganism in various ways, and has written a book - The Kind Diet - about how to transition to a plant-based life. She also often works with animal rights organizations to help with campaigns.
Speaking passionately about the lifestyle, she has said: "The amazing thing about [veganism] is that it’s turned me into a health nut, because you feel so good, you feel so different.
"So being able to do something that is good for the Earth, good for the animals and good for you all at the same time seems like such a no-brainer. It's like the biggest ‘Duh!'"