The pose and fonts are nice for your new sig, but the image quality is more "eye catching" in your previous. The backround and also the colors on your character seem to have had filters applied to them, which makes it stand out more, and just gives it a "better image quality". If you made these, i'd suggest maybe duplicating the later of your bg, and of your character images > filter > guassian blur (2.5ish) and then set the blending mode to "overlay" or "soft light" and see how it looks. Sometimes the colors get too dark, but often they make it look more vibrant which is what I believe happened with your first sig.
Still, good sigs