Insect or dead pixel inside the screen of my iMac

Since a few months ago this appeared on my iMac screen, it does not seem to be anything external since there is nothing to the touch. By the way, it seems to be an insect! I've never had anything like this happen, I know of cases on some laptops but not on an iMac. It can also be a dead pixel, but because of its irregular shape, if you see it well, it gives the whole sensation of being an insect, until you can see "wings" ... The strange thing is that during these months it has not "disintegrated" or something .. it's still there just like the first day. My main query is: here in Buenos Aires I found out in various repair services, some tell me that they can open this model (Late 2013 - the most finite screen) others tell me otherwise. But a few days ago I saw a video of iFixit (among others) on YouTube where I confirmed that it can be opened. What do you think it can be, and what do you recommend me do? While it's a small detail, I find it annoying to see that on the screen.

I attach an image. It is what appears on the "Documents" folder, right in the middle.

I hope I have made myself understood.

Thank you!