Boardview for the iPhone 8 Plus in its Intel modem variant, as the short name indicates, saved as a 379 KB BVR file. Since the 8 Plus shipped with Intel or Qualcomm basebands with different layouts, confirm your board carries the Intel modem before use. A BVR boardview shows component placement, designators and nets on both sides of the board and opens in viewers such as FlexBV. Use it to locate test points, follow rails and find the shorted component on a failing logic board.
The button opens the matching file on RM Schematics, or a source page if it is not catalogued there yet. The original attachment is from @cyberlanelectonik. Enginerys does not host this file.
How to open a .bvr file
Text boardview from the BoardView R family of tools, seen for Lenovo, MSI and Clevo boards.