The masonry snippet was recently imported from website into mass_mailing but its background image options were omitted, making it impossible to changes these images. task-2824014 closes odoo/odoo#89690 X-original-commit: a226c26255dfabff2ac10ca3ec9b56d01feb0d7e Signed-off-by: David Monjoie (dmo) <dmo@odoo.com>