I looked up a few portable freezers at my local big box store, and most of them pull about 1 amp of continuous power from a wall plug, which in my region is 120 volts. So that's 120 watts. If it uses 120 watts for an entire hour, that's 120 Watt-hours. That Jackery power station says it has a 518 Watt-hour capacity at full charge, so if we assume a 15% loss converting from DC battery voltage to AC wall voltage, we have an available capacity of 440 Watt-hours. Divide 440 by 120 and you have a freezer run time of about 3.5 hours. If the freezer were powered by 12 volts (like a car power port) you could expect slightly longer run time because there's no conversion loss in the AC inverter.

Now, a freezer will not run all the time. They cycle depending upon heat loss from insulation, environmental temps, and opening the door. If the freezer only runs half the time, we can double the time to 7 hours of expected use from a full charge of the Jackery thing. I think this is reasonable considering these units aren't insulated very well.

It says the solar panel will charge the power station in 9.5 hours so, used in tandem, we could only expect a few extra hours out of the setup before battery voltage falls enough to shut everything down.

So, those are my estimates for wall voltage. 7 hours of usable time on just the power station, and 10 hours with both the power station and the solar panel. These calculations assume the power station was fully charged, the sun is shining, and the freezer was fully frozen before losing power. On 12 volts DC you could up those estimated times to 9 and 12 hours respectively.