The fights are part of the book and not merely promotional images. That's whole point of the book. It is their "fight" book while the main event book focuses on the actual story.
@Captain Craig...Kaine is still the same Kaine as was mentioned in the flashback sequence. He was killed in the excellent Gauntlet arc as a sacrifice to bring back Kraven the Hunter. The Kravinoff clan actually thought it was Peter since they needed Parker blood. Kaine then was resurrected (again as was shown in the flashback) by the Queen at the start of Spider-Island based on the Jackal's recommendation. He was cleansed though and has new powers. He is still the same character we first met during the Clone Saga, and yeah he's doing this to basically honour Ben's memory and as part of his own redemption. Peter kind of helped him during Spider-Island. They actually had a really awesome dynamic despite everything that has happened between them in the past. They acted like brothers lol.