UG-2828GCEAF02 display module datasheet, PDF, 1.34 MB, one of several copies of the same part documentation in this collection with slightly different file names. It should contain the pin assignment, electrical characteristics, timing for the host interface and mechanical outline. For repair, it is used to probe the module supplies, check the reset and chip-select lines, and identify a compatible replacement. Compare it with the other copies, since they may be different revisions of the spec with corrected values.
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 @acodis_lcd_datasheets_EDID. Enginerys does not host this file.
How to open a .pdf file
The standard format for schematics, block diagrams, power-sequence charts and service manuals.