Using SharePoint 2013 (online), when I put either an Image Viewer web part or just an img tag in a Content Editor Web Part (CEWP) to the right or left of text in a CEWP that is in a web part zone that should be vertically aligned with the zone the text CEWP is in, the image pushes down the text CEWP.
This is a publishing site, and I've tried all kinds of variations.
Here is a screenshot in editing mode on the page where I have the image in the Header zone and the text CEWP in the Right zone:
Here is a screenshot once the page is published, with the image displacing the text down:
It doesn't matter what the size of the image is or whether it is in a zone to the left or the right of the CEWP text web part. It doesn't matter if the image is a PNG or JPG.