  We present an analysis of the evolutionary and pulsation properties of the
extremely low-mass white dwarf precursor (B) component of the double-lined
eclipsing system WASP 0247-25. Given that the fundamental parameters of that
star have been obtained previously at a unique level of precision, WASP
0247-25B represents the ideal case for testing evolutionary models of this
newly-found category of pulsators. Taking into account the known constraints on
the mass, orbital period, effective temperature, surface gravity, and
atmospheric composition, we present a model that is compatible with these
constraints and show pulsation modes that have periods very close to the
observed values. Importantly, these modes are predicted excited. Although the
overall consistency remains perfectible, the observable properties of WASP
0247-25B are closely reproduced. A key ingredient of our binary evolutionary
models is represented by rotational mixing as the main competitor against
gravitational settling. Depending on assumptions made about the values of the
degree index l for the observed pulsation modes, we found three possible
seismic solutions. We discuss two tests, rotational splitting and multicolor
photometry, that should readily identify the modes and discriminate between
these solutions. However, this will require improved temporal resolution and
higher S/N observations than currently available.
