Using the advanced setup and registry editing, these default operational settings you describe are changeable. However, it’s not necessary to isolate the image in Edge.
In MS Edge, the magnifier will magnify images while they are in context. FireFox and Chrome require isolation to magnify images because it magnifies everything except images.
Here’s a link describing the use of the MS Edge magnifier. https://support.microsoft.com/en-us/help/4028566/windows-10-change-the-size-of-text
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