Colors poem on wheels!
When the player chooses to share poems with Monika during chapter 4 of Act 2, the poem that she shares isn't actually a poem. Initially, heavily distorted rectangles of red and green show. When the player clicks, the game will check to see how the game is being played. If the game is both in fullscreen mode and running on Windows, the game will display a fake Windows 10 stop error for three seconds. Otherwise, the screen will turn black for two seconds.
Monika will appear over the aforementioned screen, commenting that she "messed up" at writing the poem. She later clarifies her intentions in her 27th topic in Act 3, explaining that she was "experimenting with different ways [she] could modify the game, and run code."