Regarding the logo on mobile devices, changing the Header Style in Appearance > Customize > Header > General > Header Layout doesn’t solve the issue, because I would like to keep the existing format for desktops and tablets, and only center the logo on mobile devices.
As for the order of the items in the gallery, changing the publish date doesn’t achieve what I need. I just want Andrew to appear centered under Anthony Sanchez, while keeping the current order of the items.