'Ant-Man' has only been filming for a few days at this point, but because they're shooting all their exteriors in the middle of downtown San Francisco, we've had no shortage of set pics. So far, we haven't seen anything particularly shocking; mostly Paul Rudd walking around with a backpack. But, it was something in the background of one of those shots of Paul Rudd walking around with a backpack. Is that a Hulk easter egg?

If you remember back to 'The Incredible Hulk' (the Edward Norton movie that is technically part of the Marvel Cinematic Universe even though it's mostly forgotten), Banner worked at a Brazilian bottling plant while he was working to control his anger issues. Not a great idea though, when a drop of his gamma-infused blood drips into one of the bottles of Pingo Doce soda. Later, we'd revisit the soda when Stan Lee, in his infamous Marvel cameo, opens up his fridge, drinks the soda and gets "gamma sickness."

We've already heard that Howard Stark, Peggy Carter and a young Alexander Pierce could show up in 'Ant-Man' flashbacks, could we also see a Bruce Banner cameo? It's not out of the realm of possibilities that someone as smart as Pym would be friends with someone as smart as Banner. It could also help tie 'Ant-Man' in to the modern 'Avengers' universe. Or, it could just be some cool set dressing for eagle-eyed fans.

'Ant-Man' only has a few more days filming in San Francisco before it moves to soundstages in Atlanta where the influx of set photos will come to a halt.

'Ant-Man' opens in theaters on July 17, 2015.