That's certainly a potential follow up hypothesis. Surely this study can be improved, but conversely not every study has to answer every question or be perfectly ecologically valid before it is worthy of publication. For all its faults, the scope of these results is clear, and worth discussing. The authors have a hypothesis - women visually assess scenes differently to men when in the context of walking through them - and have chosen an operationalization that, while not literally strapping an eye tracker to someone while they walk through campus, is a reasonable proxy for it within the time, budget, and technology constraints of the research group. This effort has produced a clear result. Future studies can now be developed that improve the design methodologically and ecologically and dig into alternatives and further nuances.