docs: Clarify environment-based screenshot ordering

docs/xml/metainfo-component.xml

@@ -1203,30 +1203,31 @@
 		</para>
 		<para>
 			The <code>&lt;screenshots/&gt;</code> tag contains multiple <code>&lt;screenshot/&gt;</code> children, where at least one of them must have the property
-			<code>type="default"</code> to indicate the primary screenshot of the software. Every <code>&lt;screenshot/&gt;</code> tag must have at least
-			one <code>&lt;image/&gt;</code> <emphasis>or</emphasis> <code>&lt;video/&gt;</code> child, but never an <literal>image</literal> <emphasis>and</emphasis>
-			<literal>video</literal> at the same time.
-		</para>
-		<para>
-			Screenshots containing videos must not be the default screenshot.
+			<code>type="default"</code> to indicate the primary and most representative screenshot of the software.
 		</para>
 		<para>
 			Optionally, a <literal>screenshot</literal> may also have an <code>environment</code> property.
-			This string property denotes the GUI environment the screenshot was recorded in, in the form of <code>&lt;env&gt;:&lt;style&gt;</code>,
-			where <literal>env</literal> is a desktop-environment name in lowercase
-			and <literal>style</literal> is a specific style that the desktop environment recognizes, e.g. <code>light</code> and <code>dark</code> for light
-			and dark themes. See <ulink url="https://github.com/ximion/appstream/blob/main/data/desktop-style-ids.txt">desktop-style-ids.txt</ulink> for a list
+			This string property denotes the GUI environment the screenshot was recorded in, in the form of <code>{env}:{style}</code>,
+			where <literal>{env}</literal> is a desktop-environment name in lowercase and <literal>{style}</literal> is a specific style
+			that the desktop environment recognizes, e.g. <code>light</code> and <code>dark</code> for light and dark themes.
+			See <ulink url="https://github.com/ximion/appstream/blob/main/data/desktop-style-ids.txt">desktop-style-ids.txt</ulink> for a list
 			of currently recognized environment and style combinations.
 		</para>
 		<para>
-			Software centers displaying the component will prefer screenshots of the current environment and style first, will then fall back to
-			screenshots of the current environment (without style), and if none of those are available either they will use the environment of the
-			screenshot marked as <code>type="default"</code> (which may be intentionally empty).
-			That way, there will always be a screenshot displayed.
+			Software centers displaying the component will usually prefer screenshots of the current environment and style, and display them first,
+			even before the screenshot marked as <literal>default</literal>.
 		</para>
 		<para>
 			In general, screenshots should be displayed in the order the are defined in in their <literal>screenshots</literal> block
-			for the respective component.
+			for the respective component on a per-environment basis (all screenshots of the same environment/style will be displayed in the order
+			they are listed in the XML, but may be moved to the front of the list as a whole depending on the current environment).
+		</para>
+		<para>
+			Every <code>&lt;screenshot/&gt;</code> element must have at least one <code>&lt;image/&gt;</code> <emphasis>or</emphasis> <code>&lt;video/&gt;</code> child,
+			but never an <literal>image</literal> <emphasis>and</emphasis> <literal>video</literal> at the same time.
+		</para>
+		<para>
+			Screenshots containing videos must not be the default screenshot.
 		</para>
 		<para>
 			The value of the <code>&lt;image/&gt;</code> tag is a direct HTTP/HTTPS URL to a screenshot uploaded to a public location on the web.