Looking through old postcards, I found this stupid modern art one...
... Wait, apparently there's a hidden message? How do I find it?
This puzzle was inspired by an escape room I did with friends yesterday. I liked the basic mechanism but the execution was lacking. So, here's my improved version.
The message is
Window, because you can spell it by overlaying a window on the image.
My idea was that
the negative space seemed important, as my instinct told me. It seemed like you could form letters out of it, but we don't know if they are even in the correct orientation. That W which could be formed at the top left could be an E rotated, and the right set of bricks looks like it has a lowercase e also rotated. (I also considered numbers for a short time, even though the puzzle is tagged word, since the same set of bricks seems to have a 6.)
Then I assumed, what if all letters were right-side up? Then it seems you could form W, I, N, D, O, and W by overlaying a grid and hence a window shape, but you can't just overlay a grid with thin lines (which is what I first thought) - the letters wouldn't form properly. But in fact, I needed thicker lines: the thicknesses of the extra space below the top frame boundary and above the top three bricks and the middle horizontal space in the right set of bricks hinted that they had to be filled with grid lines with the same thickness.
OP's help:
The mechanism itself is hinted by the very first words, "Looking through."
