Layla the boxer and Luna the Aussie have seen their mom write letters and read letters, and they came up with a grand scheme to write a letter from their veterinarian, so they don't have to go to the clinic anymore. They are not skilled forgers, about on par with an elementary school student who tries to write a note from their parents. Mom isn't fooled, but she's impressed with their resourcefulness.
I'm impressed with the acting skills of both Layla and Luna and Mom, too! Plus, this little vignette is masterfully edited to tell a simple yet delightful story without words or wasted time. You can see more of these goofy videos from Layla and Luna at TikTok.