I assume you’re talking about Discourse and not Discord and that’s a typo?
This is controlled by admin settings on the site… there are two settings specifically:
newuser max attachments- default 0newuser max embedded media- default 1
So to prevent spam and various forms of griefing, new users can’t post more than 1 photo at a time, and can’t upload attachments.
These restrictions are lifted once someone reaches Trust Level 1, by default this happens when:
- Entering at least 5 topics
- Reading at least 30 posts
- Spend a total of 10 minutes reading posts
An admin can configure all of these thresholds… so some sites may be more strict than others.
We have some more info about trust levels on our blog: Understanding Discourse Trust Levels