Like many of Microsoft's apps, Office Lens displayed some cool technology at launch but was lacking in features. With today's update, Microsoft is addressing one very obvious shortcoming of the app. You can now capture multiple items at once and merge them into a single document.
The changelog only has one new item on it: "Our top requested feature is here. Scan more than one image and save them all as single PDF, a Word or PowerPoint file on OneDrive, or simply export them as images to the same OneNote location." Office Lens includes multiple capture modes, like whiteboard and business card. This affects how the app will process the image. What's new this time is that after capturing an image, you can hit the "plus" button to take another.
When you're all done, your project can be exported as an image or a PDF. If you want to do the PDF (which includes OCR for search) you need to log in with a Microsoft account. Files are saved to your document folder in OneDrive and in OneNote.