Optical illusion

I took a photo of these curves and reflections of a bench just because I thought it created an interesting effect. After getting home, and seeing it on my screen, I noticed it actually creates an optical illusion where one can see it curving inwards or outwards...my young son son saw it right away, my husband had to look a few times and suddenly said now I see it. Which do you see first and can you see it the opposite way?

Done