This is very nostalgic to see the Software Labs disk guy mascot. My family used to get Software Labs magazine back in the early 90s, it was a print magazine where you could basically see the selection of software they have available, and then call or mail order disks of the programs to be delivered to you. I have many disks from Software Labs from my childhood, including ID and Apogee games like Halloween Harry, Cosmos Cosmic Adventure, Commander Keen and Duke Nukem 2, and in my case Software Labs never provided artwork for any of these... maybe because we were always ordering the 5.25" floppy instead of the 3.5"... This doesn't really answer your question, other than to say it doesn't seem to me that Software Labs regularly made their own cover art for shareware games (like some other shareware distributers did)... but then again Wolfenstein 3D was a big deal so they might have made an exception for this release, especially if it was so popular they were trying to have a version to sell at computer stores.
I'm sure you recognize it, but this picture seems like a higher resolution re-draw of the opening splash screen for the game.
