Framing for the Phone Screen
On a phone, a vertical video plays under a layer of buttons: tabs at the top, a column of icons on the right, and the caption, sound and account name along the bottom. Anything you put there is hidden for most viewers.
Faces in the upper middle
Keep eyes and mouths between roughly a fifth and three fifths of the way down the frame. That is where every platform leaves the screen clear, and where the viewer's eye already rests.
Titles and subtitles above the caption block
Burned-in subtitles belong just above the bottom zone, not at the very bottom where they sit under the caption. Keep them clear of the right-hand column too.
Frame for 9:16 from the start
A 16:9 shot cropped to 9:16 loses most of its width before the buttons cover anything. Plan, draw and generate vertical shots as vertical from the first frame.
One zone for every platform
If the same episode goes to TikTok, Reels and Shorts, use the "All three" box: it is the area clear on all of them at once.