This pin is similar to the first pin, it has those fine white lines that show the proportion of the bird. I like how it shows the original image and then it transforms into a pixelated bird. Low poly, looks like a fun or frustrating exercise to do.
How To : Adobe Illustrator Geometric Art. This is a very interesting type of art. I do like how it uses simple shapes to create a portrait. I know for a fact that you can do this easily in Photoshop with one of the brush tools.