My admin, Naima, has problem shown in image when she sends the newsletter to her work email. This is all Google hosted, so gmail for your domain. The problem shows up on Web and Mobile. It also shows up when she tries in an incognito window.
When she sends to me or to her personal Gmail it is totally normal.
When she forwards the broken email to another email address it is totally normal.
Her Gmail normally displays images. We have no idea what is happening or how to troubleshoot.
If this is only her, we don't care. But it it is going to be 10% or 20% of newsletter recipients it is a major problem.