If your order is a mix of items Sold by ZALORA (local), Sold by ZALORA (international), and Sold by Sellers, you will receive the items separately in different packages and on different days due to their different delivery times.
If you order items from more than one Seller, you will receive a separate package for each one as well.
Here's a handy chart to see how long your delivery will take:
For items sold by ZALORA:
For items sold by Sellers: