You can export a single slide as a JPEG using either of these methods below.
1) First, open up the slide you would like to export as a JPEG, then, click on the More option that appears on the right. A pop-up window will launch and you can select the Export Slide button. Then, choose the Export To JPEG button. Once the export is complete, it should download automatically.
2) Launch the Organize view by selecting the icon above or use the Spacebar key. Next, right-click the slide you would like to export and select Export To JPEG from the menu.