diff --git a/prosopopee/themes/material/templates/sections/pictures-group.html b/prosopopee/themes/material/templates/sections/pictures-group.html
index ccd0a0f..cb2790a 100644
--- a/prosopopee/themes/material/templates/sections/pictures-group.html
+++ b/prosopopee/themes/material/templates/sections/pictures-group.html
@@ -25,7 +25,12 @@
                             {{ image.copy() }}
 
                             <div class="picture card-image caption">
-                                <a href="{{ image }}" {% if caption %}data-caption="{{ caption }}"{% endif %}>
+                                <a href="{{ image }}" {% if caption %}data-caption="{{ caption }}"{% endif %}
+                                    data-at-450="{{ image.generate_thumbnail("x450") }}"
+                                    data-at-800="{{ image.generate_thumbnail("x800") }}"
+                                    data-at-1366="{{ image.generate_thumbnail("x1366") }}"
+                                    data-at-1920="{{ image.generate_thumbnail("x1920") }}"
+                                    >
                                     <img class="lazy" data-original="{{ image.generate_thumbnail("x600") }}">
                                     {% if caption %}
                                     <div class="caption__overlay center">