That's because [I assume] in Audacity the compression is processed into the waveform and a new peak file is redrawn. In Cubase, if you want to see the effects of compression on the waveform you have to process it with the relevant compressor plugin by right clicking the audio event -> plugins -> [compressor plugin]. You then have to select your settings and audition the results by pressing preview.
But one question, why do you want to see the results? The real question is,
how does it sound? What exactly are you hoping to learn or achieve by seeing the results?
If you'll allow me some off-the-record thoughts on this...
Back when audio was really audio there were no visual distractions to befuddle us. When you turned a knob, your ears were the primary information gatherers and when we heard what we were expecting, we stopped turning the knob. That was about it and it was a real tactile experience. Now we have computer screens and analyzers and EQ curves and waveform readouts and blinking lights everywhere. DO NOT UNDERESTIMATE THE POWER THIS HAS ON WHAT WE HEAR. The ears are easily fooled. The action of applying EQ and watching the curve change whilst listening can be a more complicated matter than you think. It is SOOOO easy to fool the ear into thinking you have just made a good processing decision when you have not.
My advice would be to forget about what the waveform looks like and
just use your ears. Your mixes will thank you for it.
Cheers
