Not really. You’ve granted the owner some rights, such as the right to host your content and present it to any user on the platform, but they don’t own it. Twitter can’t start using any art hosted on their platform for their branding, because it’s no theirs.
They can if the license you granted them says they can. Read it. These platforms usually make you grant then extensive rights. Yes they don’t own the content but given such broad permissions it makes very little practical difference.
Not really. You’ve granted the owner some rights, such as the right to host your content and present it to any user on the platform, but they don’t own it. Twitter can’t start using any art hosted on their platform for their branding, because it’s no theirs.
They can if the license you granted them says they can. Read it. These platforms usually make you grant then extensive rights. Yes they don’t own the content but given such broad permissions it makes very little practical difference.