Visible items will mainly depend on your screen resolution. You will, however, be able to scroll through the icons and lists as well as adjust the size of the timeline, as seen below. Simply use your mouse scroll wheel or touchpad scroll gesture.
Toonly: Viewing tabs and adjusting the timeline size?
Learn how to scroll through tabs and adjust the Toonly timeline size using your mouse scroll wheel or trackpad scroll gesture when items are not fully visible due to your screen resolution.