In the DCEU, Batman recognizes the hope and optimism inherent in Wonder Woman and Superman, which serves as a catalyst for him to form the Justice League.
After the success of Wonder Woman, Johns reiterated a very similar approach, this time applying it to the film side, saying the DCEU characters need to have “heart, humor, hope, heroics, and optimism at the base.”
Wonder Woman obviously embodies that hope and optimism in a much more overt way, but that looks different with Batman.
These words may be encouraging to many fans, who have pointed out that different characters manifest hope and optimism differently.