Both use animals to illustrate the letters of the alphabet which is a natural combination for kids. The poster on the left is by Lorena Siminovich proprietress of Petite Collage. It's 18" x 24" and includes a key to the animals at the bottom ($50).
Tara Hogan of Ink and Wit is the designer of the poster on the right (and above). We love the soothing combination of the blue, yellow and gray and the poster also has a touch of green - it's printed on recycled paper with soy ink and packaged in a recycled tube mailer. The poster ($60) is 16" x 20".