Dexter and Robot are the main characters in the picture and they alone should be able to draw the audience in and keep there interest. However the Dexter and Robot are lost in all the clutter. Anyone looking at the first picture becomes confused they start looking in every direction, at the flee circus in the background, the picture on the door the books in the foreground.
HINT: If you squint at the first drawing, you notice that all the values are ruffly the same shade. Now squint at the second drawing, you can now see value contrast in the darks and the lights. Your mind starts to realize that not all of the information in the drawing is important, but that Dexter and his robot are.
Another way to check to make sure your characters are standing out is to make your image very small. Look to make sure your light are on dark and your dark are on light. After making the drawing small I realized I had a few more deign issues!
After making the drawing small I realized I had a few more design problems. First was this glaring tangent. Where the end of the robot's head meets the end of the dresser. Creating one continuous line. Also All my circles in that area where about the same size as well as the head of Robot and the dresser.
The end results. Hopefully you have a clear idea as to what I want you to be looking at.