Chart, page-864

The award is not for the 'importance of the outcome' or 'robustness'. Awards for posters are not given out for these reasons.

The way these awards are given out is the committee wanders around with a drink in hand, takes a look at all the posters, has a chat with the presenters, and then they have a vote at the end of the process on which poster they like best. It is not typically an assessment of the importance of the science and most especially not an assessment of the robustness of the results. This is done at the publication stage.

It is a nice thing to get if you are at a conference, but try not to read more into it than what it is.