Question

expand the theme a picture is worth a thousand words

Answer 1

it is better to show a picture instead of telling thousands of words because picture can tell many things.

Answer 2

A picture can depict a story, a story which might require at least thousand words to narrate.

Picture allows us to visualize things thus making it easier for us to understand the situation.

For example, you may  learn about the parts of a flower in details by reading the description in words and it will involve a long description.

But if you see the picture of the parts of a flower, the description will be easier for you to understand.

So it is rightly said that a picture is worth a thousand words.