Broad license to user content
You are agreeing to hand over permanent, unpaid rights to your content so X and its partners can reuse or sell it freely.
“...you grant us a worldwide, non-exclusive, royalty-free license (with the right to sublicense) to use, copy, reproduce, process, adapt, modify, publish, transmit, display, upload, download, and distribute such Content... in any and all media or distribution methods now known or later developed, for any purpose.”
What that means: X can repurpose your personal creations for any project without compensation or further permission.
You give X a wide, permanent permission to use your posts, photos, and videos. They can modify them, share them publicly, and allow outside partners to reuse them without asking or paying you.