Based on the Chaos Marine chapter color schemes, I would assume that:





First panel: Sororitas have been fighting against "World Eaters" of Khorne, who use brute force.





Second panel: Sororitas have have been fighting against "Plague Marines" of Nurgle, who use disease and decay.





Third panel: Sororitas have been fighting against "Thousand Sons" of Tzeentch, who use magic.





Last panel: Sororitas were going to have a fight against the "Angels of Ecstasy" of Slaanesh, but the fight turned into orgy.