Firstly, you should use imgur to host your pictures, you can then use Insert Image function (its the little mona lisa icon) to actually show the image.
Secondly, here is my edit:
I looked at some pictures of hot air ballons and noticed they arent just one big cloth, they have these lines that show separations. also the basket under the balloon is reaaaally small, if you would draw it realistically you wouldn't even see it in 16x16. But it's an important part of the balloon so you should still draw it.
I also made the clouds more cloudy, they arent just blocks of white in the sky they are shapeless blobs that kind of dissolve in the air.
