best poster contest not showing thumbnail images

Hi,
I want to run a best poster contest. The files are pdfs and pptx files. I want people to vote on them as images.
I used type image/file but no thumnails appear just a default placeholder thumb for pdf or pptx
If I want to run this with thumbnail/image view of the posters or more like a photo contest do I need to convert the files to an image file type like png or jpg etc?

Advice appreciated,

Natalie

Hello Natalie,

we do not generate thumbnails for documents because in most cases they contain text.
You can convert your files into any image format (including png and jpg) and upload them to a PollUnit photo contest.

Best regards
Markus