To add mobile style overrides, click on any Emailify layer in your design, then click the Settings button in the plugin header, and apply any desired mobile style overrides for the selected layer as needed.

For example, clicking on a Text layer in your email will allow you to override its font size, line height, letter spacing, paragraph spacing, padding and alignment for mobile; whereas clicking on a Row layer in your email will allow you to override its padding, the item spacing between its columns and whether it should stack the columns on mobile (or not).

You can visually preview your mobile overrides using the preview feature in the Emailify plugin.