I wonder if it would have any problem to erase the images that are in the folder: Folder

/ media / k2 / items / src

as it is currently with more than 2gb. Or if you have some way of optimizing the images on them.

The src folder is where the original images are being stored.
If these images are not being used in your template you can discard them AFTER you have have kept a backup.
NEVER delete the folder, always keep a backup and do not remove the index.html file.