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The novel measurements of the $\gamma^\ast N \to \Delta(1232)$ Coulombquadrupole form factor in the range $Q^2=0.04$--0.13 GeV$^2$ changed the trendof the previous data. With the new data the electric and Coulomb form factorsare both in remarkable agreement with estimates of the pion cloud contributionsto the quadrupole form factors at low $Q^2$. The pion cloud contributions tothe electric and Coulomb form factors can be parametrized by the relations $G_E\propto G_{En}/ \left(1 + \frac{Q^2}{2M_\Delta(M_\Delta-M)}\right)$ and $G_C\propto G_{En}$, where $G_{En}$ is the neutron electric form factor, and $M$,$M_\Delta$ are the nucleon and $\Delta$ masses, respectively. Thoseparametrizations are in full agreement with Siegert's theorem, which statesthat $G_E= \frac{M_\Delta-M}{2M_\Delta} G_C$ at the pseudothreshold, when$Q^2=-(M_\Delta -M)^2$, and improve previous parametrizations. Also a smallvalence quark component estimated by a covariant quark model contributes tothis agreement. The combination of the new data with the new parametrizationfor $G_E$ concludes an intense period of studying the $\gamma^\ast N \to\Delta(1232)$ quadrupole form factors at low $Q^2$, with the agreement betweentheory and data.

New low-$Q^2$ measurements of the $\gamma^\ast N \to \Delta(1232)$ Coulomb quadrupole form factor, pion cloud parametrizations and Siegert's theorem