As per the question, Frankie's thought of trying out a new pair of basketball shoes despite already having a pair makes it 'a want' because it signifies his wish or desire to possess more and more pairs of shoes.
On the other hand, if Frankie tries out a new pair of basketball shoes when he does not have any other pair to wear and participate in the match reflects the 'need' as it signifies the means of survival or subsistence.
Thus, he needs these shoes to survive in the game in the latter case while in the former case, it is merely a human desire to possess more. Therefore, the first statement characterizes a 'want' while the second exemplifies a 'need'.
