Will the double passive expression have a different nuance from the single passive?

Question

While studying Korean, I came across an interesting expression in a YouTube video. In the video, the sentence '나는 남한테 내가 보여지는 것을' appeared, and it seemed like the expression '보여지다' was used as a double passive form of '보다'.

Usually, the passive form can convey the meaning with just one use, so I'm curious if there is a special reason or feeling for using the double passive form. In the video I watched, it was explained that the double passive has the same meaning as the single passive, but I want to make sure I understood it correctly.

If there is anyone who knows Korean well or has a similar experience, could you please explain the double passive expression? I'm especially curious if this expression is commonly used when learning Korean in areas like Gangnam or Hongdae.