There are several ‘A’ shapes in the image, which would be appropriate for the fourth Avengers film.
That said, you can make a case there are more than four ‘A’s.
Louis D’Esposito may not see anything in the photo (it doesn’t look like anything to me), but plenty of fans do, or at least they think they do.
Since this image surfaced on Twitter, the online sleuths have went to work and they’ve come up with some compelling answers, even if none of them have been clear cut or confirmed.