my first thought is that the bowl itself looks like a shiney surface yet no reflections of the frogs there. A light source might help to round the thing up- There should also be soem radiosity between the frogs themselves.
A tutor once said to me: "Let your mind go!" and it didn┤t come back.
Wolf@WorK aka Sketchbook
my Heavy Industrie, Military and Steampunk References/Textures (updated Oct 2012)
Nice tonal work on some of them but I think you need to study edges and the lost and found nature of edges as seen when you look at objects as well as their cast shadows on surfaces. If you get this right - and maybe even make some models to study this from - your image will have more depth and realism. They all look on the same plane and a bit cut and pasted. The frogs in the front are not grounded. I also think the definition and chromatic value should be less on the frogs which are not as important to the picture or further away. In summary, study edges. Oil Painting Techniques and Materials by Harold Speed and also anything by John Carlson will help you no end.
The frogs and the bowl look like they're from completely different pictures because they literally are. You just slapped a photo of a bowl in there.