v.1 : 무조건 출력

@if($document->getUploadedFiles())
    <div class="img-box">
       @foreach($document->getUploadedFiles() as $key => $file)
          @if(strpos($file->mime_type, 'image/') === 0)
             <img src="{$file->uploaded_filename}">
             @php
                $path = pathinfo($file->source_filename);
                $ext = strtolower($path['extension']);
             @endphp
          @endif

       @endforeach
    </div>
@endif

v.2 : 파일 갯수 1개일 땐 썸네일로, 이상이면 원본 모두 출력..

@php
    $uploadfiles = $document->getUploadedFiles();
    if ($uploadfiles !== null && is_array($uploadfiles)) {
       $filecount = count($uploadfiles);
       if($filecount==1){
          echo "<div class='img-box'><img src='".$document->getThumbnail(230,230,'fill')."'></div>";
       }
       else{
          echo "<div class='img-box'>";
          foreach($document->getUploadedFiles() as $key => $file){
             if(strpos($file->mime_type, 'image/') === 0){
                echo "<img src='".$file->uploaded_filename."'>";
                $path = pathinfo($file->source_filename);
                $ext = strtolower($path['extension']);
             }
          }
          echo "</div>";
       }
    }
@endphp