Upper level winds are from the southeast. The satellite measures sunlight reflected by the clouds and surface of the earth. The percent of sunlight reflected by the land is called the surface albedo. A cloud's albedo is generally high, but can vary with its thickness and composition.
Thick clouds have high albedos and show up bright in the satellite image.
Thin cirrus clouds have low albedos and are usually semi-transparent to sunlight. The structure of clouds in the satellite image can tell the meteorologist a lot about the weather and animations tell him about the movement of weather systems. This allows for the detection of changes in the temperature of clouds and that of the surface during the day and at night. The temperature of the clouds also indicates how tall they are since temperature is inversely proportional to height in the atmosphere. Meteorologists may also color code infrared imagery in order to more easily interpret the data.