Boardview for the Apple MacBook Pro A1708 logic board 820-00840, revision A, with the ECM3154 identifier also noted in the name. Delivered as a .brd file readable in OpenBoardView, FlexBV or ZXW-style tools. Apple uses the 820-xxxxx pattern for its logic board numbers, and the exact number on the PCB should match before you rely on locations. Repairers use this layout to locate PP rails, probe test points, track down shorts on the main power lines and identify components by reference designator.
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 @boardviews. Enginerys does not host this file.
How to open a .brd file
The most common boardview extension. Several unrelated formats share it, which is why one viewer opens a .brd and another refuses it.