Almost none of this work starts with a shoot. A client sends a footage library, a script and sometimes a reference edit, and the ad is built inside those limits. Where the library does not cover a beat in the script, motion graphics and text treatment carry it — you do not drop the line because the b-roll is missing. Working inside a fixed asset library is the normal condition of performance creative, and the skill sits in the edit rather than in asking for a reshoot.
The second constraint is the feed. Paid social autoplays muted, so every claim needs a visual and a text treatment of its own — the ad has to work with the sound off and gain from the sound on, rather than depend on it. Placements that break that rule get treated differently: an OTT spot is watched on a couch with audio on, and feed conventions read as cheap on a television.