You would probably prefer to download the 8 PNG panels (A1-D2), as they are the same data visualized. The .bin files are the raw binary files that Reto Stockli used to generate the images in the PNG files.
A short description about the BIN format could be like this: .bin files in the BMNG file repository are made of 8bit unsigned binary files, structured as 3 Channels X 86400 columns X 43200 lines. No header data, no ASCII text data in these files. You read the files as a byte array with 3 dimensions: 3x86400x43200 where the first dimension are the RGB (Red Green Blue) color triplets of the image, the second dimension are the number of columns (X dimension) and the third dimension are the number of lines (Y dimension). The image starts with 3 bytes of the RGB values of the northernmost and westernmost pixel. The next 3 values are the RGB values of the one pixel to the east of the first pixel. And so on. Geographic projection with a regular grid spacing of 0.004166667 degrees per pixel.
Open it in Photoshop but you need A LOT of memory and Version 8 or higher (e.g. I myself cannot do that): Open as -> RAW -> width 86400, height 43200 pixels, count 3, depth 8 Bits, interleaved, Header 0 Bytes.