Topic on Store talk:GOG.com
The launcher image was removed from PCGW due to it being unused at the time. The screenshot was once a staple on DOSBox related GOG releases which included it but the site went away from covering the same third-party non-game specific tool everywhere (as part of our move away from duplicating unnecessary info everywhere, no doubt).
If the tool is going to be covered, it would be on either Store:GOG.com or DOSBox, probably, but I personally do not see much relevance for it to be covered since it's ultimately seemingly just a simple frontend for editing the DOSBox configuration file.