Humour in large part derived from the satire of shitty webcomics/online serials via, for example, blatantly reused panels, and introducing a character and not even referencing them. Moreover, the shittyness is telegraphed as being due to a shitty method, as opposed to just shittyness for its own sake; poor paint fills touched up with paintbrush, awful typesetting over poorly erased text. Shittyness isn't just bizzare/mundane elements juxtaposed with a ton of deep frying either, clearly care has to be taken to have created this, with the jpeging of specific slices of the comic, making it all the more obvious because it coexists with non-jpeged space. In a later comic, just to pull a better example, you can still see the dimension-adjustment squares on part of a dialogue box, which would have to have been screenshotted and layered back in just for the effect.
SBaHJ also runs on the emphasizing of a disjointed, sometimes manic cadence, emphasized by the erratic panelling, dialogue broken up into odd chunks or clearly cut together and overedited, varying in size font, emphasis (e.g. TOKING UP -> on a joint.... -> S T O N E D).
And of course, the second part of the humour, the surreal is actually that, surreal. Instead of just satirically playing up various tropes to large degrees, throwing in wild juxtaposition, it genuinely puzzles with the car sequence from the 7th panel onwards. Composition is yanked at a 90 degree angle to what we are used to, turning into a non-ending of bizzare repetition that clearly isn't playing on extant tropes or jokes. It's a non-sequiter that is nevertheless telegraphed as inevitable in its form (wild swerves and strange conclusions) without being given warning as to its content or timing, avoiding the low-effort pit of lolsorandum humour.
no, I really don't have anything better to do tonight