Little Big Planet wont download as disc image file

whenever i download LTB it will show up as a SFB file. I have downloaded and extracted other games like Kya: Dark Lineage and Sly Bandicoot and they both came out fine. I use winRAR to extract my files downloaded on chrome and then extract/drag them to my PS2 game folder. Am i doing something wrong or is something broken? This has been an issue for me for about a month.