forgejo/templates/repo/issue/view_content/attachments.tmpl

<div class="dropzone-attachments">
	{{if .Attachments}}
		<div class="divider"></div>
	{{end}}
	{{$hasThumbnails := false}}
	{{- range .Attachments -}}
		<div class="gt-df">
			<div class="gt-f1 gt-p-3">
				<a target="_blank" rel="noopener noreferrer" href="{{.DownloadURL}}" title="{{$.ctxData.locale.Tr "repo.issues.attachment.open_tab" .Name}}">
					{{if FilenameIsImage .Name}}
						{{if not (StringUtils.Contains $.Content .UUID)}}
							{{$hasThumbnails = true}}
						{{end}}
						{{svg "octicon-file"}}
					{{else}}
						{{svg "octicon-desktop-download"}}
					{{end}}
					<span><strong>{{.Name}}</strong></span>
				</a>
			</div>
			<div class="gt-p-3 gt-df gt-ac">
				<span class="ui text grey">{{.Size | FileSize}}</span>
			</div>
		</div>
	{{end -}}

	{{if $hasThumbnails}}
		<div class="divider"></div>
		<div class="ui small thumbnails">
			{{- range .Attachments -}}
				{{if FilenameIsImage .Name}}
					{{if not (StringUtils.Contains $.Content .UUID)}}
					<a target="_blank" rel="noopener noreferrer" href="{{.DownloadURL}}">
						<img alt="{{.Name}}" src="{{.DownloadURL}}" title="{{$.ctxData.locale.Tr "repo.issues.attachment.open_tab" .Name}}">
					</a>
					{{end}}
				{{end}}
			{{end -}}
		</div>
	{{end}}

</div>