>>5319324it is common practice to regularly invert the canvas horizontally to give you fresh perspective, as if it was a drawing you hadnt seen before. if you work on a drawing for a while the mistakes start melding in with the rest and its easy to not see them at a glance, doing this makes those mistakes stand out. The joke is that a perfectly regular looking drawing (even a line in this case) will look horribly skewed and wrong when inverted.
>>5319335they drew their lineart on the sketch layer by mistake, except for a small part they put on a different layer, so now they have to do all the lineart again on the proper layer.
