Not all files are visible over MTP
This is apparently a known bug in Android which is not even acknowledged by Google since Oct 2012, bug #2 — depending on the method of creating files on the Android device, these files may remain invisible when accessing the device using MTP, until the device is rebooted.

Known workarounds include:


Use USB storage mode instead of MTP, if it is supported by the phone. This is apparently not an option for LG Optimus L5 (e610), because this phone has unified internal storage (file storage is in /data/media on the same ext4 filesystem as /data), which cannot be exported as an USB storage device.
Clear data of the “Media Storage” app, then use the SDrescan app to rebuild the media database (discussed here).
Share files over the network using third-party apps such as AirDroid or one of Samba server apps (in the latter case you will need to have root to make the server reachable from most clients, including Windows).