Hi Chris1968,
Since you are showing a specific customer journey, it is highly likely that there are other customer journeys that have sent this email, resulting in inconsistent data.
Dynamics for Marketing allows you to bypass the manual use of segments and customer journeys to send Marketing Emails through the send now button, although customer journeys and a static segment are generated in the background to track the insights.
So if you don't create another trip and add an email to its image, it may be because the email was sent by clicking the send now button.
Looking at documentation this option is good for when the contact list is 30 or less?
https://learn.microsoft.com/en-us/dynamics365/marketing/email-send-now
Yes, You can send to a maximum of 30 contacts:

When you want to write a quick email and send it to a few specific recipients, this is the time to do it without spending extra time creating segments and customer journeys.