Archive named SNOTE, a name that gives no brand, board number or revision. At 1.01 MB it is roughly the size of a compressed laptop schematic, though the contents cannot be confirmed from the name alone. After extraction with WinRAR or 7-Zip, look for the board number on the title block and compare it with the marking on your PCB. If it is a schematic, it is useful for tracing power rails, locating components and diagnosing shorts, but only once the board identity is confirmed.
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 @generalschematics. Enginerys does not host this file.
How to open a .rar file
Compressed archive — the usual wrapper for a schematic + boardview pair or a BIOS + EC set.