Please note how to write the word "camera"

There is surveillance inside, please pay attention to your words and deeds. Please smile while being monitored.

There is surveillance inside, please pay attention to your words and deeds. It means there are surveillance cameras inside, pay attention to your personal behavior. During surveillance, please smile is a humorous reminder that there are cameras. It can also be used as a slogan to warn the public to pay attention to the cameras. Practical and effective.