This is a video capture of the "Good morning, Jacob!" demo running in the Atari ST emulator Hatari.
The demo credits "Mr. Coke" of Avena and "The Innovator" of NEWline as the main coders.
This demo is unique because the animation is achieved with nothing more than a text file.
Using special escape sequences in the Atari ST's VT-52 text mode, the cursor can be moved around the screen. This technique is very similar to what ANSI artists did on IBM PC-compatibles to create ANSImations.