The best thing about this is the "pressure" effect. Looks like that balloon is really pressing up and into the mother kangaroo. It's both awkward and appealing. My favorite aspect of these types of pics are the "pressing" effect of one surface bulging against another equally rubbery surface.
Just great. i've always liked this pic. And Kangaroos are my favorite animal, so having one ballonified ( sorta ) is a definite plus.