It is ideal that the WebChat logo reflects your brand so that your customers know that they are communicating with you.
In WebChat, the chatbot has two "statuses": minimized and expanded, and you can choose a different
image for each of them.
Regarding the font, you can share the image/s that you want us to apply to your chatbot on your Trello board. In the Personalization & Review list, find the WebChat Customization card and attach the files there.