To properly view the assets and all their animations, you need to put the files in the "Sprite Sheet" folder (the .atlas, .skel, and the sprite sheet) into a program that can view Spine animations. For Favorite Item scenes, you should drag two of the .atlas, .skel, and the sprite sheet into the program and set one of them "idle" or "expression_0" and the other to "bg_idle" or "bg_expression_0". The one I would recommend for its ease of use is SpineViewer program by ww-rm https://github.com/ww-rm/SpineViewer.