You're mixing up "re-sampling" with compression. Re-sampling doesn't exist, you can't re-sample a file. When you compress a file, you take existing information and compress it into a smaller file (FLAC=8000+kbps -> mp3 320kbps) so the file goes from 35MB -> 7.48MB.
Sampling has no relative affect on the size of the file to my knowledge...
On the FLAC version (if the file has about 5000 kbps) then you will see about 5000 dots in the 1 second range you look at all arranged so the dots are compressed to seem like a line.
When you look at the 320kbs plot, you will see the same trend, but the dots will be more spread out throughout the graph and as a result, you will have a less "informative" graph.
I'm interested to know where you got FLACs at 8000kBps given that CD quality WAVs are a constant 1411kBps, most of my FLACs are ~800kBps and my few 96kHz/24 tracks are barely over 2000kBps. If we were talking kbits per second perhaps...