  We propose a one-channel, simple model to describe the dynamics of ultracold
dipolar molecules around a F\"orster resonance. Slightly above a specific
electric field, a collisional shielding can take place, suppressing the
molecular losses in a gas. The overall description of the quantum physical
mechanism comes back to the dynamics on a unique energy surface, which depends
on the relative distance and angular approach of the molecules. This surface
enables to interpret how the dipole moments of the molecules are induced and
interlocked by the electric field and the dipole-dipole interaction during the
process, especially when the shielding is triggered. Averaging the relative
angular motion over a unique partial wave (the lowest one when the ultracold
regime is reached), the model reproduces well the behaviour of the rate
coefficients observed experimentally and predicted theoretically [Matsuda et
al., Science 370, 1324 (2020); Li et al., Nat. Phys. 17, 1144 (2021)]. This
economic model encapsulates the main physics of the quantum process. Therefore,
it can be used as an alternative to a full quantum dynamical treatment and is
promising for future studies of collisions involving more bodies.
