Do you face the issue with other. jpg files? I just tested and looks like the size should just increase ~30% after uploading. Also, could you provide the file you had issue with?
I have just tried with the file you provided, but the size of XFDF is ~13MB. I was trying with our online sample here - JavaScript PDF Viewer Demo. Also I was using this blank PDF file as attachedblank.pdf (8.5 KB)
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