Describing, what I've done, was not subject of your first request. Check your first question, and make it more precise. What is so difficult for understanding?

JOSM wiki provides no description or explanation for the map-upload-dialog phrase "Update native". So, start request via Google!

Hi, magicgate,
update native is a pre-select comment in JOSM version 9329 upload-dialog window without possibilities for changing it.

Best regards, x4porter