It's possible he drew that a while ago.
If he had a burnout or mental meltdown or something, that could have been how he coped and recovered. Just drawing stuff, without any preasure of deadlines or anything.
Then now he posted it because he felt that one showed his state of mind.
Or maybe he's just trolling his readers now and sees for how long we'll stick around on promises of "But today I'll really post it!"