When it comes to GIF images we analyze all frames. We know that offensive content can be present in just a small subset of frames, so for safety's sake we will process them all.
Remember that for GIF images each frame will be analyzed. So we will count one operation per frame (or more if you run more complex analysis on your GIF).
Please keep in mind that there is a limit to the number of frames that will be analzyed in a GIF image. GIF images with a large number of frames (20 or 50 frames, depending on the model you use) may be rejected as it would take too much time to process in one single request. To process such GIF images you can either split the GIF images into several GIF images with fewer frames, or get in touch to ask for a custom plan.