To change the sender image in Klaviyo when your email account is linked to Outlook (and not G-Suite), follow these steps:

1. Check Klaviyo's Default Settings:
   Klaviyo might not automatically update the sender image based on your Outlook profile picture. The sender image in Klaviyo is often determined by the settings within Klaviyo itself or from Gravatar, a service that associates email addresses with profile pictures.

2. Set Up a Gravatar:
   - Visit >Gravatar](https://en.gravatar.com/) and sign up using the same email address you use with Klaviyo.
   Upload your desired profile picture to Gravatar. This image will be associated with your email address and could be used by Klaviyo when sending emails.

3. Check Klaviyo’s Branding Settings:
   In Klaviyo, go to the Account Settings under your profile.
   Look for an option to customize or change the sender image. If available, you can upload your preferred image directly.

4. Update in Email Templates:
    Ensure that your email templates in Klaviyo are using the correct "From" address linked to the Gravatar or Outlook account where you've set the image.
   Sometimes, Klaviyo allows you to add a custom image or logo in the header of your emails, which might override the default sender image.

5. Contact Klaviyo Support:
   If the above steps don’t work, consider reaching out to Klaviyo support. They can guide you through the process specific to Outlook accounts.