ᐅ Is that mold inside the window shutter box?

Yesterday, I noticed the following on the roller shutter box of three windows. Could this be mold?

It is hard to see clearly in the photos. But it almost looks like mold.

Looks like it.
Cold, uninsulated roller shutter box → warm air condenses on it → mold.
Since the affected area is very small and the cause is logical and easy to fix, I would say it’s not a major issue.

Roller shutter boxes are insulated.

Then they are poorly insulated or not installed professionally. In the third picture, you can clearly see the mold and condensation buildup. This is always assuming proper ventilation is maintained.

Our construction manager will come by tomorrow to take a closer look.

The rooms are ventilated four times a day for 15 minutes each time (cross-ventilation).