I had a Eureka moment.

I understand what the sign means.

It means not much. It is a crossed thermometer and it means that the
fridge is unable to hold the preset temperature. Duh.

Why is it unable to do so, is the $64,000 question.

I opened up the back. I observe the following:

1) The condenser fan is running
2) The compressor (big heavy black part with copper pipes going in and
out of it) is quite hot to touch and is seemingly not running.

i