Gwenview does not terminate when close it. It stays hidden in the memory. When you start Gwenview again, a new instance of Gwenview is created. The instances consumes memory.

You have to kill the dead instances via process monitor.

Reproducible: Always

Steps to Reproduce:
1. start Gwenview
2. close Gwenview window
3. check memory/processes
Actual Results:  
Gwenview does not terminate, the instance stay in memory

Expected Results:  
to terminate Gwenview and free memory