In the following, we describe the analysis of SARS-CoV-2 spike stabilized in the prefusion state by two proline substitutions in S2 (S-2P). We will objectively demonstrate that the flexibility of the spike protein should be understood as a quasi-continuum of conformations, so that when performing a structural analysis on this specimen special care has to be paid to the image-processing workflows, since they may directly impact on the interpretability of the results.