It is the turn of the border wallpaper
It adds color to Dock in addition to the frame that fits the full screen iPhone screen. And on Lock Screen it colors the buttons and Control Center indicator.
20 sets each
▶︎ iPhone 11 Pro Max/XS Max
▶︎ iPhone 11 Pro/XS/X
▶︎ iPhone 11/XR
This is not the only one in the series for iOS 13.0/13.1.