Here's how it works:
One of the wait-staff brings in an order written on a ticket. They stick their copy of the ticket on the back side of the hot line window. The chef sticks his copy of the ticket on our side of the line and reads off the order, e.g., "Pick up: beet tartare, crostini, an arugula salad! Order in: two ravs, a marinara and a cashew cream!" At which point I would will scramble to get my stuff together, probably shuffling in place while picking up the wrong plate for bread, looking about for the ring mold to put tartare in and then overdressing the arugula salad (think Jerry Lewis in oversized shoes).
After bungling about there for a few minutes, I'll place the appetizers up in the window (a shelf above the cold line), call out something like, "Apps in the window!" They'll then get taken out to their table by the food runner, who will cry out something like, "Table four going out!"
From there we pick up other tickets that have come in or we dally about reorganizing and cleaning our work stations, prepping food for later in the evening or the next day, or just gaze into each others eyes longingly until we're told to fire the next course on that ticket. At which point I'll busy myself with some dough stretching, distribute some toppings, and try not to burn myself while shuttling pizzas in and out of the oven.
There are some nuances to this whole process. Different dishes take different amounts of time to make. My pizzas require between three and five minutes once they're in the oven, while most of the pasta dishes probably require between two and four minutes and portobello steaks need more time. So in order to make sure all the food is ready simultaneously, pizzas get started first and then once they're about half-way finished, pastas get thrown in the boiler. At this point our timing for stuff is pretty good, so food tends to get out relatively fast and grouped together properly. Of course, if we end up with a large table ordering, it can delay the orders for everyone else in the restaurant.