In the last months, new drawings made by J.K. Rowling have appeared in some sections on the Pottermore website, but no one noticed them. They were not announced by Pottermore Staff, so they stayed there until someone recognized them. There are new three handwritten drawings by J.K. Rowling, and four that we already knew but now available at higher quality.
The new images are the following.
These images are part of the Peeves, Potions and History of Quidditch World Cup articles.
The already know images are now available at higher quality. They were previously shown at video interviews or were part of older editions (like Harry at Privet Drive).