Clarify and update screenshot recommendations

doc/development/documentation/styleguide/index.md

@@ -1091,47 +1091,51 @@ However, they should be used sparingly because:
 - They are difficult and expensive to localize.
 - They cannot be read by screen readers.
 
-If you do include an image in the documentation, ensure it provides value.
-Don't use `lorem ipsum` text. Try to replicate how the feature would be
-used in a real-world scenario, and [use realistic text](#fake-user-information).
+When needed, use images to help the reader understand:
 
-### Capture the image
+- Where they are in a complicated process.
+- How they should interact with the application.
 
-Use images to help the reader understand where they are in a process, or how
-they need to interact with the application.
+### Capture the image
 
 When you take screenshots:
 
-- **Capture the most relevant area of the page.** Don't include unnecessary white
-  space or areas of the page that don't help illustrate the point. The left
-  sidebar of the GitLab user interface can change, so don't include the sidebar
-  if it's not necessary.
+- **Ensure it provides value.** Don't use `lorem ipsum` text.
+  Try to replicate how the feature would be used in a real-world scenario, and
+  [use realistic text](#fake-user-information).
+- **Capture only the relevant UI.** Don't include unnecessary white
+  space or areas of the UI that don't help illustrate the point. The
+  sidebars in GitLab can change, so don't include
+  them in screenshots unless absolutely necessary.
 - **Keep it small.** If you don't need to show the full width of the screen, don't.
-  A value of 1000 pixels is a good maximum width for your screenshot image.
+  Reduce the size of your browser window as much as possible to keep elements close
+  together and reduce empty space. Try to keep the screenshot dimensions as small as possible.
+- **Review how the image renders on the page.** Preview the image locally or use the
+review app in the merge request. Make sure the image isn't blurry or overwhelming.
 - **Be consistent.** Coordinate screenshots with the other screenshots already on
-  a documentation page. For example, if other screenshots include the left
-  sidebar, include the sidebar in all screenshots.
+  a documentation page for a consistent reading experience.
 
 ### Save the image
 
+- Resize any wide or tall screenshots if needed, but make sure the screenshot is
+  still clear after being resized and compressed.
+- All images **must** be [compressed](#compress-images) to 100KB or less.
+  In many cases, 25-50KB or less is often possible without reducing image quality.
 - Save the image with a lowercase filename that's descriptive of the feature
-  or concept in the image. If the image is of the GitLab interface, append the
-  GitLab version to the filename, based on this format:
-  `image_name_vX_Y.png`. For example, for a screenshot taken from the pipelines
-  page of GitLab 11.1, a valid name is `pipelines_v11_1.png`. If you're adding an
-  illustration that doesn't include parts of the user interface, add the release
-  number corresponding to the release the image was added to; for an MR added to
-  11.1's milestone, a valid name for an illustration is `devops_diagram_v11_1.png`.
+  or concept in the image:
+  - If the image is of the GitLab interface, append the GitLab version to the filename,
+    based on this format: `image_name_vX_Y.png`. For example, for a screenshot taken
+    from the pipelines page of GitLab 11.1, a valid name is `pipelines_v11_1.png`.
+  - If you're adding an illustration that doesn't include parts of the user interface,
+    add the release number corresponding to the release the image was added to.
+    For an MR added to 11.1's milestone, a valid name for an illustration is `devops_diagram_v11_1.png`.
 - Place images in a separate directory named `img/` in the same directory where
   the `.md` document that you're working on is located.
 - Consider using PNG images instead of JPEG.
-- [Compress all PNG images](#compress-images).
 - Compress GIFs with <https://ezgif.com/optimize> or similar tool.
 - Images should be used (only when necessary) to illustrate the description
   of a process, not to replace it.
-- Max image size: 100KB (GIFs included).
-- See also how to link and embed [videos](#videos) to illustrate the
-  documentation.
+- See also how to link and embed [videos](#videos) to illustrate the documentation.
 
 ### Add the image link to content
 
@@ -1152,8 +1156,11 @@ known tool is [`pngquant`](https://pngquant.org/), which is cross-platform and
 open source. Install it by visiting the official website and following the
 instructions for your OS.
 
+If you use macOS and want all screenshots to be compressed automatically, read
+[One simple trick to make your screenshots 80% smaller](https://about.gitlab.com/blog/2020/01/30/simple-trick-for-smaller-screenshots/).
+
 GitLab has a [Ruby script](https://gitlab.com/gitlab-org/gitlab/-/blob/master/bin/pngquant)
-that you can use to automate the process. In the root directory of your local
+that you can use to simplify the manual process. In the root directory of your local
 copy of `https://gitlab.com/gitlab-org/gitlab`, run in a terminal:
 
 - Before compressing, if you want, check that all documentation PNG images have