After Sayori's death, when you write poems, you only have Natsuki and Yuri chibis on the left.
However, when you click on certain words, you can see another chibi jumping. At first, I thought it was Sayori, but after triggering the chibi jump twice, accidentally of course, I have noticed straight hair and white ribbon, such as Monika's.
I am sure that I am not the only one who noticed it, but not sure if anybody was able to make a Monika poem out of it, which may have changed the story if you manage to spend some time with her.
If you were able to make a Monika poem, what would be the words she is interested in?