It‚Äôs not customary. It‚Äôs just to show respect to indigenous women. He‚Äôs showing how they should be greeted and held to high regard which is missing in American culture. It‚Äôs lighthearted but I also think he means it. It just shows how he respects women, especially powerful women who come from a long lineage of teachings, traditions, etc. Which is becoming more rare because of how small the indigenous population is and elders who pass on traditions and stories are becoming scarce. I think like he‚Äôs always recognizing that they are INDIGENOUS and he‚Äôs on their land.