Trivia: During Batman and Superman's fight scene, there is a shot of some graffiti that says "Quis custodiet ipsos custodes?", which is Latin for, "Who watches the watchers?" This is a reference to "Watchmen", which was also directed by Zack Snyder, and also references the theme of both films.
Trivia: The lightning tornado dream sequence echo voice thing is the DC Extended Universe version of The Flash, The Flash appearing in mysterious form, kind of like a dream, and possibly from a different point in time, is very much a reference to Crisis on Infinite Earths where Flash was appearing to various heroes trying to warn them of what was to come while he was busy dying later in the story fighting the very same threat.
Trivia: S.T.A.R. Labs is a research facility originated in Superman #246 some 45 years ago, and currently a key component of CW's The Flash TV series. The lab was also the employer of Silas Stone in Teen Titans - and it's Silas who we see creating Cyborg at the lab in that truly spine-tingling video recording on Diana's laptop.