The frog

[Wladimir D]

It's just the lines that are in all of the openings. Only this one has been painted incompletely. I'm not sure if at this scale we can say that it was intentional.

 Yes, Koen , I also took into account to the scale of the drawing. But the question arises, if the painter, with his "jeweler's" pen, is able to draw a hollow eye (circle) in the lady  (not a point and not a blob!), then why can not he draw a 5 times bigger object (tadpole)?
 However, many people are not able to see these details in the manuscript on a natural scale without the use of glasses. How did the painter do it, if at the time of writing the manuscript, the loupe (officially) did not yet exist?
PS / You can qualify this tadpole and as a symbol of "YIN-YAN" on plant f38r.