UK PM Gordon Brown meets Former PM Margaret Thatcher at 10 Downing Street

The transcript features a brief interaction with Lady Thatcher, where she is asked if it's good to be back. Initially, she nods in response, and the speaker confirms her non-verbal answer by repeating the question and noting her nodding.

What can be inferred from Lady Thatcher's nodding?

Discuss the significance of the interaction between the speaker and Lady Thatcher.