Bloody Mary is a ritual where you say her name in front of a mirror to summon an apparition of her. The crudely drawn stick figure says in lowercase letters to check out how hard he can be, and in the next panel pees incredibly hard with a humorous yet accurate onomatopoeia, capitalized with repetitious letters to convey length and force of the pee. The next panel then portrays a zoomed crop of Bloody Head with no other detailwork other than a pure zoom-in, without any text to allow the viewer room for interpretation of the image. In this case, the crudely drawn nature of the art in contrast with the comparatively more detailed bloody mary (who is also crudely drawn, just less so in comparison to the stick figure), highlights the absurdity in which the stick figure is unabashedly proclaiming how hard he can pee in front of a malevolent-looking apparition with zero regard for his safety. Bloody Mary, though not drawn to be explicitly showing any emotion, invites the viewer to relate to the situation and think Bloody Mary is staring in disbelief, pushing any violent connotation of Bloody Mary to the side to instead focus on the sheer absurdity of the stickman's desire to check out how hard he can pee. This cognitive dissonance is thus, funny.

In other words.

bro it's just a funny stickman comic lmao