Marvel Studios President Kevin Feige has confirmed a previous theory regarding a hidden cameo by Janet Van Dyne in 2015's Ant-Man Quantum Realm scene, according to ScreenRant. That's in addition to the Ant-Man/Wasp flashback from earlier in the film.
"In the first film it was, we got a glimpse of it for people who like to go through frame-by-frame, there was a little silhouette of Janet as the Wasp in there, which is a big story element in this movie," Feige explained at a press junket for Ant-Man and the Wasp.
Here's the image in question:
The presence of a Quantum Realm Easter egg was revealed prior to Ant-Man's man's release, with director Peyton Reed spilling the beans himself.
“There’s an event that happens to Scott Lang in the third act of the movie,” said Reed in 2015. “He goes into a place that’s been unseen in any motion picture ever before, and when he goes into that place - I don’t think Scott Lang sees it, but if you’re sharp, if you’re a keen, sharp audience member you might see something or someone in that environment.”
At the time, a tardigrade spotted in the Quantum Realm was credited as the Easter egg, though Feige has now confirmed that the true Easter egg is the vaguely Wasp-shaped silhouette seen as Scott Lang shrinks.
The hunt for the original Wasp and the first adventure of the new Wasp, her daughter Hope Van Dyne, is a central element to Ant-Man and the Wasp, the sequel to the 2015 film, due out in theaters July 6.