A boardview (component placement) file (board LA-7731P). Shared as “QAM00 LA-7731P (REV 1.0) (A00) (BDV).brd” — a .brd file, 223 KB.
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 @alischematics. 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.