A frame's proportions affect the relationships inside it. When browsing portfolios carrying the name Xu Fai, compare horizontal, vertical and square presentations if they are available. Notice how much room a subject has to move or face into, and whether an edge brings an object close to the viewer. These observations concern the displayed image, regardless of the format used at capture.
If the same photograph appears in more than one crop, compare the boundaries before judging the versions. A website thumbnail may crop automatically, so consult the complete view offered on its page. Do not infer an author's preferred composition from a preview alone. Record which presentation you assessed so that your notes remain useful when returning to the work later.