Difference in file of RPD created from POF vs Create config data RPD (Generate output_file_auto.rpd)

Hi Team

I have a cylcone V code , with almost 32MB. When i convert using to RPD using POF, the new RPD is almost of same size, that is 32MB.

But when i check box "Create config data RPD (Generate output_file_auto.rpd) option , using SOF as input file, its 4MB.

I referred to below link for more details, but did not make sense to me.

can you please elaborate more.

https://www.intel.com/content/www/us/en/programmable/quartushelp/17.0/mapIdTopics/mwh1465494315836.htm