These colorful tropical frogs have become a classical object for static close-up photography. But in a world where almost all colorful frogs pose on even more colorful flowers like movie stars, I like the simple and natural look of this shot.
The technique is plain, but such a vividly-coloured animal does not need anything more. Moreover, this gives the feeling the picture was taken in the frog's natural environment. The focus is good and in place, although the focal area could you some more sharpness and clarity. My guess the shot was freehand and the shutter speed of 1/30 s is a little too low for that. The composition is well balanced. I would like to see more of the frog shown, but on the other hand the eye-level point of view is the best for this kind of pictures. The background is clear and the blurred yellow spots have found a perfect place behind the blue frog to create a harmonious combination and emphasize on the animal's vibrance even more. The only slightly distracting detail is the dull bluish stripe on the upper edge.
My overall evaluation is strongly positive. There are slight flaws in the technique, but the cadre is nonetheless captivating.