I can't see it either, but I'm interested to since this is something that I've considered making as well. It would certainly be a good tool, in the same way that a body condition chart is useful for dogs and cats. Without getting to see your chart I would describe fat vs obese similar to other condition charts do.
A 3 (ideal) Visible fat stores in the head and tail, palpable fat stores in the abdomen. May have some fat stores in the underarm developing. The spine is defined but not prominent. The contours of the bones in the hips are defined but not prominent. The lizard in cross section is roughly wedge shaped with a flatish belly. The tail is rounded with a thicker portion near the base. The lizard can flatten out.
A 4 (over-weight/fat) A fat lizard will still probably be storing most of its fat in typical areas, the abdomen is getting round and fat is starting to get stored in the neck and chest more. The spine is less defined. The belly sags or is rounded (not related to eating). Lizard cannot really flatten out so well.
A 5 (obese) would be rounded to the point that they loose most definition skeletal definition, especially in the back and tail. These lizards look swollen to me. In cross-section the lizard would be more oval shaped than wedge shaped. Spine may appear sunken relative to the sides. Fat rolls around the neck and hips.
Cooper, I'm not sure if you are familiar with condition charts but its not so much a matter of scoring high, but being 'fit'. I agree that its probably best suited for grown dragons, there are lots of captives that could be healthier if their owners recognize signs of being too thin/too fat. Recognizing body condition in non-human animals can be a challenge without some cues.