Nation theme is using Team content type for displaying your team members.
Team Teaser Layout is defined in nations.layout.yml with unique name: team_layout and template file team-layout.html.twig located at template/layout folder. We use Teaser view mode to show this layout.
Go to Manage Display Team content type. Click on Teaser view mode, scroll down and click on Layout for team in teaser and choose Team Teaser Layout. After that, put fields into region exactly as image below, you will have style same as image above.
Note: Click on gear for each of icon to input/modify class for each of field.