Small RAR archive, 56.7 KB, holding a BVR boardview file for a phone the name abbreviates as iP5S, apparently the iPhone 5S logic board. BVR boardviews open in viewers such as OpenBoardView or compatible commercial tools. They let you search a component or net and see where it sits on the board, which helps with locating test points, tracing lines and finding the part behind a short. Confirm the board in front of you matches the model before trusting part placement.
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 @SMART_PHONE_SCHEMATICS. 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.