You can customize the look of the header in the branding panel of your Snap-ins deployment setup. You can change the colors, font, font size, and add a background image. For visitors using a desktop browser, you can display a welcome message in the header.
The header also conveniently disappears as the visitor scrolls, because it does take space away from their chat. Visitors can scroll up to open it or scroll down to close it, unless there’s a notification.