Hello Lodewijk
Here is the list of the 13401 images uploaded yesterday that don't include {{Wiki Loves Monuments 2017}} (and were not flagged as bot): https://archivos.wikimedia.es/wikimedia/es/wlm/non-wlm-uploads_20170902.html
For the record, there were 7332 uploads (7451 including bots) that did embed {{Wiki Loves Monuments 2017}} template.
I don't know who would volunteer to review them, but if there's interest, a tool could be done to provide such lists.
Best regards