The new smartphone is expected to feature a design similar to the iPhone X with Face ID but make some compromises for a lower price. Those could include using an LCD screen instead of OLED, an aluminum frame, a single lens camera, and no 3D Touch.
Kuo says that the price of the new iPhone will affect shipment projections. If it's priced at $699, Apple is expected to ship around 105-155 million units. At a higher price point of $799, Apple is expected to ship 95-105 million units. The price will likely depend on "whether Apple ultimately sees the new 6.1-inch LCD model as the successor of iPhone 8 or 8 Plus."
Other differences for the 6.1-inch model included the use of a non-stacked logic board and a rectangular battery pack.
Apple is expected to launch three new iPhones this fall. The other two will purportedly have 5.8-inch and 6.5-inch OLED displays. More details here.