According to the famous iPhone leak blog named “Macotakara” from Japan, the upcoming iPhone 11 and iPhone 11 Max might be thinner with a bigger display screen. They had also recently leaked that the iPhone 11 would have 3 cameras on the back.
The iPhone 11 is to have a 6.1 inch OLED sized screen which is between the iPhone XS and XR screen, and that is very much closer to the Samsung Galaxy S10. The iPhone 11 is to be 0.15 mm thinner than the iPhone XS, making is much slimmer in design.
On the other hand, the iPhone 11 Max is to have a 6.5 inch OLED display and is to be 0.4mm thinner than the iPhone XS Max. Therefore, the iPhone 11 Max might have the same screen size as the iPhone XS Max.
Since the upcoming iPhones might be slimmer, we are expecting them to be much lighter compared to the iPhone XS and XS Max. Heavy iPhones tend to break easily when it dropped which is why Apple might be focusing on making it a little more durable.