No but in all seriousness: It's being able to pat a partner on the back when things go awry, reaffirm that everything will be alright and then help them resolve the problem at hand and maybe even tell them where they fucked up, if that's the case. A situation I can think of is when my gf got a letter from her health insurance demanding 35.000€ because she forgot to hand in the papers that document her income. Just being compassionate doesn't help in that situation. She was panicking and crying so I had to calm her down etc. But once that was done, I had to help her take care of the thing at hand in a constructive manner e.g. calling the insurance company, collecting paperwork, writing an E-Mail - all that jazz.
Like I said above: It is also about being strong enough to also criticize your peers. Compassion does not always mean making people feel good. Sometimes it's the most compassionate thing to point out mistakes and wrongdoings even if it hurts them.
Well I used to be a person that always had surface level head-pat things to say, when things got bad but I eventually figured out that I'm great at solving problems so I stuck to that. I also learned that critcising friends is important if you want a friendship to last.