Uploading files to a website is not anonymous either unless you do it through an anonymizing network.
If you share a file to someone, they see which account sent it. If you sent a file through this only the site itself knows and possibly not even that when they don’t keep IP logs.
If you're using software to hide your IP address (VPN, or TOR) that also removes the IP log aspect, I would imagine.
Rules (WIP)
Uploading files to a website is not anonymous either unless you do it through an anonymizing network.
If you share a file to someone, they see which account sent it. If you sent a file through this only the site itself knows and possibly not even that when they don’t keep IP logs.
If you're using software to hide your IP address (VPN, or TOR) that also removes the IP log aspect, I would imagine.