In-Universe:
The U.S.S. Defiant, a Klingon Bird-of-Prey, an Excelsior-class vessel and a Miranda-class vessel dodge enemy fire while coming up with a plan to destroy the power station.
Production:
The Digital Muse V2 CGI model is used in this scene. This confirms that this is the same model used in the episode "Valiant' because the registry number on the nose is not the Defiant's NX-74205, but the Valiant's number: NCC-74210.