I pulled the picture(Reuters) from here:
https://www.dailymail.co.uk/news/article-6300649/Caravan-migrants-swells-5-000-eye-US.html.
looking at the couple of videos...seems like there are “minders”
https://www.youtube.com/watch?v=meZenJFXVxY&feature=youtu.be
not really walking ?