Dial indicator is the best and most accurate. Barring that, you are lucky that it is the rear wheel which makes it easier to spin it in place without lateral movement.
You need a solid stable surface to work from. If you have them, set up two jack stands beside the wheel. Take whatever you have that will not damage the wheel- a hardwood broom handle works well. Place the broom handle across the top of the two jack stands- two stands makes the broom handle more stable. Rotate the wheel while slowly pushing the end of the broom handle closer to the wheel until it touches. If it touches in only one spot, that spot is not in the same plane as the rest of the wheel.
If you don't have jack stands, a bucket or any thing can be used because this is just to give you an idea. To have any meaning you need to know how much run-out there is. The run-out needs to be accurately measured with a dial indicator. It should be measured in both planes. The rim can be bent to the point that it can easily be seen by eye and still be well within Honda's allowable run-out limits. It is quite surprising how much Honda allows.
From what I see in that photo, I highly doubt that it is anywhere near the Honda limit. If you don't feel any vibration or other strange rotation related symptoms, don't worry and go ride.
