Yes, that would be a digital modulation. That is decidedly not what is being done with the bird. The input data is the "PNG" of the bird, which is then not digitally modulated, but converted to an analogue signal and later redigitized. If the file has been converted to a series of pulses at different frequencies (the equivalent of your black and white squares) that would be a digital modulation. I am not arguing that this is not possible. My original comment explicitly says I would like to see a follow up with actual modulation. But just because it is possible to run dialup over an analogue phone line does not mean that calling your grandma on that same phone is a digital communication system. Some computers back in the day could modulate and record data on commercial audio cassettes. That does not mean that if I record something off the radio and play it back later that's a digital copy of the song.