Actually, it looks like focus might be a red herring here. When I took this screenshot I had selected the first paragraph of my previous comment (i.e. a text selection not in a editable form field.) Selecting (highlighting) text and capturing that in a screenshot seems like a reasonable user expectation.
Bug 1887093 Comment 4 Edit History
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Actually, it looks like focus might be a red herring here. When I took this screenshot I had selected the first paragraph of my previous comment (i.e. a text selection not in a editable form field.) Selecting (highlighting) text and capturing that in a screenshot seems like a reasonable user expectation. (Correction: the text selection is visible beneath the screenshots overlay only until you move focus using tab or F6, then selection disappears)