We released an update to the web messenger that makes it possible to upload an icon to represent the bot. To change your icon (by default it’s the Flow XO logo), edit your bot and you’ll see a new icon upload control.
This means that paying users can now use an entirely customized messenger - no Flow XO branding at all. 
Hi John,
Can you let me know how I can change the FlowXO logo? We having a paying account (as well as my sandbox here).
Thanks,
John
When you edit a web messenger bot, you should see a field there you can upload an image to be used as the logo?
Your bot on Messenger should have the icon that is assigned to your FB page, is that what you mean?
Hmmm will need to do some more prodding - on my test page it show’s my test fb page icon, on some of the beta customers the last line of every communication is ‘Sent by FlowXO’.
If you’re referring to the “Sent by FlowXO” message in your Facebook page inbox, that is only visible to page admins - basically, FB is showing you who sent the message (could be you, another admin, any connected API, etc).