When I do step and repeats (i.e., press walls) that use the same image in a repeating pattern, apparently InDesign actually repeats the same image each time it shows up. If the repeating image is large and complex, I get a huge PDF file. Is there a way to repeat an image but have it only appear "in the file" once? Some kind of "pointing" to a single instance of the image?
Placed images (as opposed to pasted images) in Indesign are by their very nature pointers to an external image file, so there is no way to slim down the size of your exported PDF other than by playing with the export settings. Other than that, ensure that your file is placed in Indesign at 100% and at the correct resolution for your desired output. If you open the PDF in Acrobat, you can also save as a reduced size PDF which may help.
Not the answer I wanted to hear, but thanks.