Question about Purelink Mini DisplayPort| Thunderbolt — HDMI (Typ A)

According to the vintage of the IMac, it is certainly a 4K model and therefore the IMac cannot be used as a display for the MacBook.

The easiest way is to share the screen via the IMac, so you can also operate your MacBoock.

Thank you very much for the answer! It's a pity that it doesn't work with my model. Would be very happy if there was a solution.