Answer:
Because Jose's coffee shop is in the 1st stage 'Increasing Returns to Factor' as per 'Law of Variable Proportions'
Explanation:
Law of Variable Proportions states : As variable factors are employed on a fixed factor
Jose's Coffee Shop is in 1st stage 'Increasing Returns to Factor' of TP increasing at increasing rate, MP increasing : Such because the variable factors are insufficient as per the fixed factor, their employment creates better division of labour & specialisation benefits and utilise fixed factor more optimally. This increases each additional labour's efficiency.
Eg : 1 worker would have to take the order from customers, communicate it to the kitchen, arrange the table for them, get the order to their table. Employing more labour at this stage would streamline the process much better & worker's MP will rise.