You can add a specific custom logo for a touchpoint. Note that if you are having a company general logo, the custom logo will override the company general logo in surveys.
1. Go to "Touchpoints"
2. Click the name of the touchpoint
3. Click "CUSTOM LOGO"
4. Choose a file and then click save
Take into consideration that the logo should have a transparent background, that way the logo shows up nicely in the survey background.