It is hard to definitively state that this is Wong's transitional film without seeing what his next project looks like ("2004", I think), although the lack of the voice-over narrative and the more polished look of "In the Mood for Love" seems to point in that direction.

Incidentally, if I remember the Voice article correctly, "In the Mood for Love" was not only shot somewhat in conjunction with "2004", but there were also some reshoot overlaps involving actors Maggie Cheung and Tony Leung who were also working a Hou Hsiao Hsien film.  So, maybe there is something of style influence that resulted from the experience.

*PLOT SPOILERS*
Regarding the ending of the film, I didn't necessarily see use of the country of Cambodia as a specific allusion to something.  What I had interpreted from the film was Mr. Chow's continued feeling of wandering, which also expounds on the film's theme of transience - not only with respect to love and relationships, but also the life stages of existence (an early image of the film are the two moving into their respective apartments).

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