I see it now:Looking at the image it's set to 10v per graticule thus about 80v full scale. This puts 58 volts right about where the trace is on the right hand side of the display. That clipped peak appears to represent 74 volts. This also puts the lower level to the left at about 20 volts...
So 20 squared / 8 time 0.707 puts it at 35 watts average power ... with a peak at around 480 watts ... more than enough to make your years bleed. As I commented earlier I've worked on movie theatre equipment that isn't driven this hard.
The lower left is 16 V
The peak is 74, 74 - 16 ~ 58 (full scale)
the center line is 0, ~ 1 wave cycle
So -24 to 34 ~ 58 pk to pk
Full scale is 2 mS ~ 500 Hz for the partial wave cycle
V rms ~ 35/sqrt2 = 25 V
Assuming 8 Ohm ~ 78 W avg,
peak 156 W
With 89 dB speakers ~ 108 dB