Its not about being jealous only. IN fact, it is not about that at all. Both Australia and England traditionally get themselves involved in mind games, building pressure and effecting thought process of the opposition by such remarks and statements, there media being the spearhead! With the commercialization in the international game, this habit and trend have reached non Aus-Eng games as well but you will see that it is these two teams still who are most involved in such trolling. Aussies did it with Indians, we faced this in the past as well, Ashes are always full of such incidents.
Personally, i think it is ok since such things keep the interest in test cricket alive.
The team WONT read too much into this and Cook better worry about what he will be serving us in Old Trafford rather than our celebrations!! Not those fish n Chips again