"It is not in the stars to hold our destiny but in ourselves. - William Shakespeare"
Update: I went through all of the campaign missions again, and then again, and I haven't found anything related to Destiny. I've looked in a lot of places, did a lot of glitches, and did a lot of Easter Eggs hoping it would "activate" something. Sadly, I was wrong.
I then thought maybe it doesn't have to be a hint through a picture, but maybe through a song in the game. Well, the first song I thought of was when you turn on the Easter Egg for Club Errera. Well, I finally got the song and reversed the lyrics but sadly, nothing.
Hopefully, you guys got lucky and found something related to Destiny even if it is small. Lastly, those pictures I said I would upload won't happen. I went back and looked at the pictures again and again, and came to the conclusion that they're not related to Destiny and they're in-fact just Reach things.
tl;dr