Image is an essential element of a technical document. While preparing a manual or a release note, you need to include a screenshot for a process or step. Here are some points to consider while adding an image to a written text;
Ensure the image included correlates with the mechanisms, processes, or steps that you are trying to clarify.
Always reference an image in the description before its placement. Also, include numbers and titles. Some document generator tools like; Sphinx automatically generate numbers for images.
Use appropriate labels and captions. Besides, used labels and captions should match the text description. For instance, if you are describing the "Add icon" of a UX design, do not call it "Add icon" in the image and "icon to add" in the text.
Use an image when it contains copyrighted information. Also, anonymize critical information if you are using borrowed images.
Avoid using blurry and unclear images. While adding screenshots in a technical document (manual and release note), take a clear picture using screen capture tools such as; Snagit.
An image need not be mandatorily added to the document. However, it can help your audience to self-evaluate a process. Some concepts are so complex. Instead of using an image, it is best to enhance the text.
As a bonus tip, do not exaggerate or misinterpret the original scale of an image. It affects the readability of the text.
Keep writing :)