Condensation in exhaust pipe

Last week I did a compression test: result: 80, 90, 175, 150
After running the car in reverse for 15 minutes without a coolant (need to re-park)...
The next day, I realize I run the car (RSX type-S 05) without a coolant...
So I put every parts back in the car and then look at the exhaust pip and noticed a condensation in it (similar to the stuff you see in an AC unit..)

Feeling afraid of damage cylinder head, or piston, or engine block; I did a compression test again: result: 80, 90, 170, 150.. very similar test result like the previous week..

BUT why is there a condensation in the exhaust pipe??