I am new to LoRa and I would like to get some confusion on chirp-based modulation process clarified. I was reading the very good thread Understanding the relationship between LoRa chips, chirps, symbols and bits

My additional question is: up or down chirps change frequency from Fmin to Fmax. Now, clearly all chirps in a spectrometer diagrams look the same since they (mostly) all have same frequency change (again Fmin to Fmax or viceversa). But am i correct that although is not visible in those type of diagrams, during that frequency change process is where the magic happens? Because if we'd look in detail there we would see per-symbol phase changes in order to modulate a specific code or sequence of raw-bits (e.f. 7 bits symbol)? In other terms the phase-change pattern is specific to a symbol whereas the frequency change is the same for all possible symbols?