For each of the evidences that we collect in our document, an image will be added. In principle, these will be the default ones in the tool, but you have the option of modifying them as you wish.
As a group administrator you can change the style of the image associated with the evidence used in your policies, except for biometric signature or fingerprint evidence, since in those cases the images of the signature and fingerprint captures are used, respectively.
To do this you just have to access the menu Styles > Custom images evidence and upload a file in png format with the image you want to change for the evidence.