To change the mobile header that is visible in the top right corner of the system, follow the below steps:
Within the System area, click the Settings page.
Use the Brands drop-down and select the brand to be changed.
A window will appear containing two tabs, main details & appearance and payslip details.
Click the Main Details & Appearance tab.
There is a section called mobile header where a preview of the current log in screen is shown.
To change the current image, click Upload Mobile Logo.
A File Explorer window appears.
Browse and select the image required. then click OK.
Click Save.