I’m beginning to suspect that the creator of the comic SMBC (aka Saturday Morning Breakfast Serial) has a bit of a kinky side. I base this purely on the number of examples of his work that I’ve found suitable to feature here.
The latest example is below. If you look at the hover text on the original site’s posting it says he once joked about this on old Twitter and a domme said she’d done in plenty of times. I’m not surprised by that. Kneeling on nasty things is a time honored punishment. Lego just adds a whimsical touch.
Personally, I’d rather take a heavy beating over kneeling torture. The very small number of times I’ve been forced to kneel on rice or similarly painful surfaces, I’ve had to safeword within a minute or two. I almost fainted on one occasion. Guess I just have particularly bony knees.

You can find Becky on 
You can find the original fullsize version of this
Artwork is by the late great 
Hopefully Graham does a better job with the serving tray than these two clumsy maids. Artwork here is by 
If you like this then you can find more at
I believe this is by the artist