According to quantum chromodynamics, at sufficiently high energy, the structure of hadrons reveals a dynamic equilibrium between gluon splitting and gluon recombination - a phenomenon known as saturation. The process of diffractive photonuclear production of a J/ψ vector meson provides a direct insight into the gluon composition of hadrons. The J/ψ production as a function of momentum transferred in the interaction, quantified by the Mandelstam-t variable, serves as an excellent probe for studying the structure of hadrons within the impact-parameter plane, because different ranges in t are sensitive to the dynamics of the gluon field at varying spatial size scales. The ALICE Collaboration has measured the energy dependence of incoherent photonuclear production of J/ψ mesons off lead ions, at sNN=5.02 TeV, for three Mandelstam-t intervals. The energy dependence of the photonuclear cross section at the highest |t| range measured, (0.81