Update: Paprika 3, released in November 2017 for iOS & macOS, supports adding multiple large images to a recipe. Description, ingredients, directions, notes and nutrition can also have images embedded in them. Use the recipe editing toolbar to assist you in inserting the text to link to images.
Paprika currently supports adding only a single thumbnailed image to a recipe. The original image, if added from a website, will be linked to. If the app if able to load the linked image, it will show the larger online version when you tap/click the image. That feature (the loading of the larger image) is available on iOS & Mac.
Currently recipe fields such as ingredients, directions, etc, are plain text and cannot have images added to them.
Multiple large image support is planned for a future version.