Back to the subject, a bit serious. So I=myself thought it as like giving thanks for the harvest-and due to the northern climate in Canuckyland thats earlier as in the deep south of their borderr. Just like here in EUR its earlier in Sweden/Norway as it is in the middle: Germany etc where its still earlier as in the mediterranee south.
Giving praise/thanks for a plentiful harvest of whatever grows locally is deeply ingrained in about any agri-culture and sure the Thai know how to. Of course always with choosing a ḿiss (whatever grows there, watermelon or cucumber....) and parading her (or a she/he sometimes) through the baan=village.
Every now and then in these modern times someone steps up and proclaims it can be a him, beautiful of course, its Thai after all, but this did not really catch on. The tipical katoey then always run mad about these unique chance to win a contest yet again.