Time in comics is flexible. Each panel shows a single event, which is usually accompanied by a length of dialog, which must take some time to say. This disparity is usually accepted if it isn't taken to extremes.
But often, characters will exposit when it's most needed: at the story's climax, when both the intricacies of the plot and the intensity of action hit their highest.
While the Heroes [...] [tvtropes.org]