Use Photoshop’s Layer Comps feature to show different pages / states of site. Exported JPGs are not necessary. The Layer Comps panel should allow the developer to click through every page and state of the website. There should be no out of sync Layer Comps (exclamation mark in panel).
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Layer comps in Photoshop are a handy way to show the different pages, posts and states of a web site. It is important to ensure they are updated and correct before handing off the design file for programming.