Back in the days before Easter Egg hunting became a full-time job for some people, comic book movies were already deeply embedded in the culture of adding references for fans of the comics to find. It just felt like an organic relationship from the start, and it's only got more complex and obsessively consumed since.
Film-makers like Zack Snyder and James Gunn pride themselves on layering their references to encourage multiple viewings, and that's a good thing to encourage, given how much tends to be stuffed into comic book movies these days.
And beyond even the more overt comic book reference points - which can sometimes distract from noticing more subtle, inventive details not ripped from the page - there are clever touches that only the most observant of fans will have noticed. Even on multiple viewings.
Look a little closer and you'll find even more revealing details...