This technique is used quite a lot to get an image styled url of an image in your twig file.
use Drupal\image\Entity\ImageStyle; // on top function THEMENAME_preprocess_node(&$vars) { if(($node->getType() == 'partner_logo') && ($variables['view_mode'] == 'teaser')) { $id = $node->field_logo->entity->getFileUri(); $url = ImageStyle::load('partner')->buildUrl($id); $variables['image_url'] = $url; } }
Then, in your partner-logo--teaser.html.twig:
<div style="background-image:url('{{ image_url }}'); background-size: cover"></div>