Evolution of the same cloud in the high- (High_B, top) and low-magnetisation case (Low_B, bottom). The first three columns display the column density projections of the cloud at equal SFE (from left to right: 0.1, 3 and 6%). The last column shows how the giant H II region reshapes the environment, showing the cloud after 0.3 Myr from the birth of the 100 M_⊙ star. White dots mark the position of the sink particles, while blue dots highlight the ionising stars within the domain. The red dot represents the 100 M_⊙ star from which the main H II originates. The grey dashed lines mark the filamentary structures retrieved by DisPerSE. These snapshots display the role of the B field in shaping the cloud structure (single hub vs sparse filamentary network) and influencing the timescale of the SF event.