The Blue House claims the First Lady was just wearing a simple butterfly pin, but as Dr. Tara O points out, this butterfly had far more meaning to anti-US groups in South Korea:
President Trump arrived in South Korea on June 29, 2019 after the G-20 meeting in Japan. The next day, he visited the DMZ and met with Kim Jong-un. On the 29th, the South Korean First Lady is spotted wearing a light blue butterfly brooch near President Trump. The light blue butterfly is a symbol adopted by anti-THAAD, anti-U.S. groups in South Korea.
First Lady Kim Jung-sook (김정숙) also wore the light blue butterfly pin the day before on June 28, 2019 in Japan at the G-20 meeting during the group photo session and the dinner banquet.
East Asia Research
You can read more at the link, but the First Lady was not the only one to wear the pin, other ROK officials did so as well during Trump’s visit. The blue butterfly has been become the symbol for all the anti-THAAD protesters in recent months.
Probably the most offensive thing about the anti-THAAD protesters is that it is based on lies that the electromagnetic waves from the radar are going to cause cancer and kill crops.
If the residents want to go measure electromagnetic waves they can do it right now. They can purchase their own detection device and stand at their homes or farms and see what electromagnetic waves they detect. They are not going to detect anything though because a group of Korean reporters were invited to the THAAD site on Guam and have already measured electromagnetic waves and found nothing.
This is simply not in my backyard protests that have been coopted by the usual anti-US groups that have little to do with the merits of the THAAD system and the ROK First Lady is apparently supporting this nonsense.