First we loved it on TV, then on DVD, and now on Netflix; we've never really had to stop watching Friends. And yet despite spending all that time in Monica's apartment, this one little thing might still have gone unnoticed.
Look out the kitchen window here in Season 1. You can see right onto a rooftop next door:
Now it's a brick wall with a window in it:
Now it's just a plain brick wall:
And then it's a black abyss:
Finally, here it is in Season 10:
There's a window, but it doesn't look like the one from earlier, does it?
Remember when the Friends thought they knew everything about each other?
What do you think is up with the window?
Source: Hello Giggles