Workflow options specify settings for all files output from Camera Raw, including the color bit depth, color space, and pixel dimensions. Workflow options determine how Photoshop opens these files, but do not affect how After Effects imports a camera raw file. Workflow settings do not affect the camera raw data itself.
You can see and change these Workflow settings at the bottom of the Camera Raw dialog box.
For square-pixel cameras, choosing a smaller-than-native size can speed processing when you are planning a smaller final image. Picking a larger size is similar to upsampling in Photoshop.
For non-square pixel cameras, the native size is the one that most closely preserves the total pixel count. Selecting a different size minimizes the resampling Camera Raw needs to perform, resulting in slightly higher image quality. The best quality size is marked with an asterisk (*) in the Size menu.