I believe that the authors use a design that is appropriate to their research objectives. They compare people who interact face-to-face with people who interact through screens. They find that couples who interact face-to-face are slightly more able to generate creative ideas. It is important to note that the effect, which seems robust, is not very large, but that does not detract from its relevance. There was no reason to expect a large effect. 

They interpret that this greater capacity for idea generation can be explained by the fact that in a face-to-face interaction one can look less at the other person's face (in online chatting the gaze is more focused on maintaining contact with the other person), so that attention can be fixed on more elements. That there are differences between offline-online meeting seems solid. That the difference comes from the gaze is more speculative. In my view, they do not theoretically justify in a clear way why this should be the case. However, the authors make an important effort to test their explanation and rule out alternative explanations, such as that the online meeting is simply experienced as more unpleasant.

Regarding the measure of ability to select higher quality, more creative ideas, the authors themselves give it less weight in the discussion of their results. I think they are right to do so. Their results suggest that there is a certain tendency to select better ideas in video call groups. If one generates fewer ideas, one is more likely to be able to detect among these fewer ideas which one is the best.

The authors cautiously discuss their results. They indicate that face-to-face meetings may increase creativity, but they make it clear that creativity is not the only criterion for determining how work dynamics are organised. Other elements such as cost or staff preference need to be taken into account. They suggest, and it is consistent with their findings, that if telework is to be included in the design of workplaces, then in that format you should try to reduce the meeting component for idea generation and these tasks should be done face-to-face. I repeat: the result, the difference, the effect is small. This does not take away the fact that sometimes a single creative idea, more or less, can change the future of a company, of a work group.

Like all research, it has its limitations and lines to follow. On the one hand, the experimenters eliminated from the video calls the idea of a person observing him or herself, which is common in many teleconferencing programmes. Thus, their design is slightly different from how video calls are typically designed for many. Perhaps more importantly, partially, their research compares face-to-face meetings (the usual so far) with online meetings (the less common). To some extent, therefore, the difference between online and offline can be confounded by the experience or handling of these communicative dynamics. The authors test this to some extent, but it is something they rather tiptoe around. Perhaps as the system of working by video call becomes more widespread and we learn new patterns, some of the adverse effects of this system will disappear. Or maybe not. It is something that, in my view, remains open and will be worth following up.