Following the Windows page and clicking on the egg'd window twice. The second time:
>https://deltarune.com/thepoorchildren/
Window name:
>Therapy
Oh fuck, the Third Hospital Room theory is real.

>>529510104
>>529509660
>>529509921
>>529509247
Also, the windows page, the correct one has a little egg where the others don't, in the stained glass.

If you inspect the page, you see there are two separate window.png, and switching between the two you notice the difference.