This snippet opens with a little bit of detail, then uses the comma to go into the main event.
Frozen with fear, I watched the yellow-white flames make a ragged brown line up the pink fabric of my skirt and climb my stomach.
Notice how the detail is short, while the main event is elaborate.
In the examples below, we've kept the event simple. If you want to write a more elaborate event, you can.
Terrified of what might happen, I ordered a pizza.
Ashamed of myself, I called Stewie.
Doubled over in laughter, we gasped for breath.
If we were to read the original snippet more closely and break the main event down further, you would see how the action is expanded point by point:
Let’s write some similar variations with extended action.
Lost for words, I watched Marnie stuff the tacos into her bag and then carry on talking like nothing had happened.
Stuck outside, I watched the fat golden sun make a glowing river along the rooftops before it finally sank into the ground.
Pleased with myself, I watched the wiry-haired rabbit follow a delicately cautious path along the right-hand edge of the classroom and sneak out the door.