The following is going to be a description of both the pre-9.0 update classic 3DS HOME Menu and the post-9.0 update new 3DS HOME Menu. Sorry if I missed anything, or failed to describe anything accurately enough to be understood.
Old HOME Menu (pre-9.0, old 3DS only):
The old HOME Menu had a basic design, which would be partially updated across various system updates, with the introduction of 3DS Miiverse and the feature to hold L and R simultaneously to activate the camera instead of holding either L or R. Before the latter feature was introduced, the L and R button silhouettes were also fully black, as opposed to outlined in later updates. The colors on the bottom screen are also sharper.
The selection border around the icon is completely rounded, thick and solid, and it is not glowing, meaning it is just a static green color. When an application icon is selected, a "select" sound with two "pick" sounds combined is played, instead of just one "pick" sound with the new HOME Menu. When the application is opened, the border emits green square-shaped rings from itself. Also, it literally took just one click to open a HOME Menu sub-application such as Game Notes, Friend List, Notifications or Internet Browser, and the aforementioned sub-applications do not have a banner as with the other applications. The HOME Menu Settings section is just comprised of a section to set both the screen brightness and the power-saving mode, accessed from a sun icon on the top-left corner of the bottom screen next to the Enlarge/Shrink icons. The "Open/Manual/Save Data Backup/Close" commands do not have rounded sides.
New HOME Menu (New 3DS, post-9.0 on old 3DS):
Although it may look similar, the new HOME Menu has an improved design over the old one, similar to the 3.00 PS3 update or the New Xbox Experience update for the Xbox 360. This HOME Menu was introduced with the New 3DS, being bundled with all New 3DS firmwares (such as Japan-only 8.X firmwares), before eventually being expanded to Old 3DS (XL) and 2DS with update 9.0, which also introduced HOME Menu themes worldwide. Aside from activating the camera, a new feature was also added to take a screenshot of the top or bottom screen from the HOME Menu, which was later updated to take both screens at once optionally.
The colors on the bottom screen are now clearer, brighter and slightly more camouflaged. The selection border around the icon is now only comprised of four corners, and it is constantly glowing while slightly growing and shrinking. When an application icon is selected, just one "pick" sound is played, and when the application itself is opened, the app icon emits circle-shaped rings from its center. The HOME Menu sub-applications are placed in the top-center corner of the screen and now have specific banners as with the other applications, and can be selected with the D-Pad, Circle Pad or C-Stick (New 3DS). The HOME Menu Settings section is highly improved, accessed from a house-and-wrench icon where the sun icon originally was, and the Enlarge/Shrink icons have been moved to the top-right corner of the screen. The "Open/Manual/Save Data Backup/Close" commands now have rounded sides.
Old HOME Menu (pre-9.0, old 3DS only):
The selection border around the icon is completely rounded, thick and solid, and it is not glowing, meaning it is just a static green color. When an application icon is selected, a "select" sound with two "pick" sounds combined is played, instead of just one "pick" sound with the new HOME Menu. When the application is opened, the border emits green square-shaped rings from itself. Also, it literally took just one click to open a HOME Menu sub-application such as Game Notes, Friend List, Notifications or Internet Browser, and the aforementioned sub-applications do not have a banner as with the other applications. The HOME Menu Settings section is just comprised of a section to set both the screen brightness and the power-saving mode, accessed from a sun icon on the top-left corner of the bottom screen next to the Enlarge/Shrink icons. The "Open/Manual/Save Data Backup/Close" commands do not have rounded sides.
New HOME Menu (New 3DS, post-9.0 on old 3DS):
The colors on the bottom screen are now clearer, brighter and slightly more camouflaged. The selection border around the icon is now only comprised of four corners, and it is constantly glowing while slightly growing and shrinking. When an application icon is selected, just one "pick" sound is played, and when the application itself is opened, the app icon emits circle-shaped rings from its center. The HOME Menu sub-applications are placed in the top-center corner of the screen and now have specific banners as with the other applications, and can be selected with the D-Pad, Circle Pad or C-Stick (New 3DS). The HOME Menu Settings section is highly improved, accessed from a house-and-wrench icon where the sun icon originally was, and the Enlarge/Shrink icons have been moved to the top-right corner of the screen. The "Open/Manual/Save Data Backup/Close" commands now have rounded sides.
