The conducting may be over once the concert has finished and you’ve managed to do all the etiquette correctly, but the conductor’s job is never done! There will be people to thank, not least the musicians, and there may well be people who gather outside your dressing room to congratulate or ingratiate. There may be drinks or dinner after the concert with managers, soloists, agents, sponsors, donors and all sorts. This may or may not be what you want to do after conducting a concert, but it is a necessary part of the job, and is particularly vital in North America.
In the amateur or youth orchestra world, your post-concert duties may be somewhat less glamorous: collecting in the music or putting away the chairs!