Add specific social media image

src/pretix/control/forms/event.py

@@ -488,6 +488,15 @@ class EventSettingsForm(SettingsForm):
         help_text=_('If you provide a logo image, we will by default not show your events name and date '
                     'in the page header. We will show your logo with a maximal height of 120 pixels.')
     )
+    og_image = ExtFileField(
+        label=_('Social media image'),
+        ext_whitelist=(".png", ".jpg", ".gif", ".jpeg"),
+        required=False,
+        help_text=_('This picture will be used as a preview if you post links to your ticket shop on social media. '
+                    'Facebook advises to use a picture size of 1200 x 630 pixels, however some platforms like '
+                    'WhatsApp and Reddit only show a square preview, so we recommend to make sure it still looks good '
+                    'only the center square is shown. If you do not fill this, we will use the logo given above.')
+    )
     frontpage_text = I18nFormField(
         label=_("Frontpage text"),
         required=False,

src/pretix/control/templates/pretixcontrol/event/settings.html

@@ -96,6 +96,7 @@
             <fieldset>
                 <legend>{% trans "Shop design" %}</legend>
                 {% bootstrap_field sform.logo_image layout="control" %}
+                {% bootstrap_field sform.og_image layout="control" %}
                 {% url "control:organizer.edit" organizer=request.organizer.slug as org_url %}
                 {% propagated request.event org_url "primary_color" "primary_font" "theme_color_success" "theme_color_danger" %}
                     {% bootstrap_field sform.primary_color layout="control" %}