Different size heads on juvenile beardies

Hi everyone! I have a question about the different head sizes of juvenile Beardies. When I bought my first Beardie at the petstore I noticed that all the baby dragons in the enclosure had these huge heads on little body's. I have to say they were pretty adorable. Since they were all that way and I have never seen Baby's or juveniles before I thought they all must look like this. I bought one and he eventually grew into his head. I think he is a male although I am not positive. He does seem like though that when he is full grown he is going to be a good size with a nice size head. However, an even size of course to the rest of his body. O.K. so the next time I go to the pet store and every time since to buy crickets I stop buy the Beardie enclosure and check them out. Well, after that one day all the Beardies I see now all have normal head size, proportional to their body and size. So I am confused. And all the Beardies that I have seen on the web as well have had normal size heads. So why did that one batch all have heads way bigger than normal and not proportional to their body's? Is there something wrong with them? He seems very healthy.