macOS Storage – Is It Safe to Delete ~/Library/Logs Content?

By design intent, files stored in ~/Library/Caches should always be safe to delete, at least as long as the application isn't running. You can mitigate any poor programming bugs by moving them to trash and then rebooting the mac before you empty the trash as this ensures whatever programs are running can still write files to that old cache directory but will be forced to make a new Cache folder the next time it starts.

In your specific instance, the folder/files in question are created by iPhoto when you start a slide show. It seems that they do not get removed when you exit iPhoto later on so you have to remove them manually if you want to recover the disk space.

Yes, it is safe to delete it, if you are sure you want to lose those backups.

To do so, in a more elegant way, just:

1. Open iTunes Preferences
2. Click Devices
3. Locate the backup for the iOS device you want to delete, select it, and click Delete Backup.
4. Confirm you wish to remove the selected backup by clicking Delete Backup.
5. Click OK to close the iTunes Preferences Window.

Extracted from Apple's support document about iOs backups.

Confirmed: Deleting through iTunes will delete all the backUp files of the selected device.