The answer to this example puzzle is RESPONSE. When you go back to the previous screen, you can enter that answer in the text box.
After you do that, one or more new challenges will appear on the Top Screen. So after you take a second to enjoy your congratulations for entering RESPONSE correctly, you will want to go back to the Top Screen again.
Hang on to your notes from solving this and other activities. Later on, there might be a "meta-puzzle" which makes you re-use things you saw earlier.