This screenshot was taken on Colon's GD Browser. If you click on the 'moons' icon on someone's profile in GD Browser, this screen pops up, showing how many different difficulties of levels the user has beaten. These screens also exist for classic and demon levels, and include daily levels, weekly demons, and gauntlets. However, there is a counter at the bottom of the platformer stats to track daily platformer levels, which don't exist in-game... yet. I can only speculate at this point, but it's possible that Robtop plans to add platformer daily levels to the game, which would be really cool to see. I don't know if this appears in the actual game, though - I'm yet to check. And I'm also not sure if there already is confirmation of this from Robtop - there might be, I really don't know.
Thanks to GD Colon for the GD Browser. https://gdbrowser.com/
