One time I was talking to a friend, and out of no where she told me she saw me through my window the day before. We live in the same neighborhood, so she is often going by my house, so at first I didn't think much of this, especially since my room faces the front and at certain angles you can see into my room, even though I always have the blinds down.
But then I asked her what she saw me doing, and she told me I was laying on my floor. I thought back to what I did, and realized I was on my bedroom floor at one point reading a book. But the floor is below the windows, and I didn't think you could see anything of my room no matter what angle you are at if it is below the window level. This isn't the only time she has said something like this. I find it strange, and was wondering if anyone knows if there are ways someone could see into my room even if the blinds are shut and something is below the window level. Because I would like to figure out how she could see in, and fix it, because honestly I find it a bit creepy that my whole room can be seen by anyone passing by.
If anyone can help, thank you, I know this is a bit random but I was just wondering if anyone could help.

I think it depends on which way you tilt the blinds and on what floor your room is on. (I don't know how she could see you on the ground though, that confuses me.) You can try changing the angle of your blinds and then going outside to check if you can see inside (remember to look from various distances from your house). I searched a bit and found this video- it's like 6 minutes and I didn't feel like watching it, but maybe it can help.

https://www.youtube.com/watch?v=G9vkuFflkE8