Images are not displaying in outlook.

Question

We are sending emails under phishing campaign to all the users, and we want the email to look legit and delivered to inbox. Initially, we have tested the scenario by sending emails to 1-2 accounts and found the emails were moving to quarantine, but once we added the domains and ips combination under advance delivery in defender portal, emails were going to inbox.

But still on those emails we have attached some pictures which are not displaying and showing as below.

We want those pictures to display, so that our phishing campaign will be successful. Microsoft is saying to display those images you have to add the domains under safe sender in outlook, which we do not want, as it may allow forged messages to pass through. and also not good for security. What is the other way to fix this issue, how the images can be displayed over the emails only for those phishing simulation emails.