One person noted that Musk's hatred for the hashtag has made the site "unusable and boring."
The pair met at Donald Trump's Florida mansion.
Some have taken it as the first glance of a major character.
'Disease' seems to have brought on some strong opinions.
"It seems he’s gone further and further towards the dark side..."
The billionaire owner of X "has been a fantastic thing for freedom of speech," the shadow cabinet minister said.
"I seriously think this is bigger than the Oasis reunion."
The Beetlejuice Beetlejuice actor described one explicit message as "just the beginning of what was to come" on the platform once known as Twitter.