"About this mac" not showing correct Storage usage

Hi everyone,

I've recently restored a TM backup of my old Macbook Pro to my new rMBP which contains about 120GB worth of photos in my Photos Library but the Storage section of my "About my Mac" section reports only a few gigabytes of photos and lists most of the data as "Other":

I've tried disabling and re-enabling Spotlight indexing through System Preferences or even via command line shell with "sudo mdutil -E /" but it always goes back to the same.

All other counts (like Audio, Apps and Movies) are ok but Photos seems to be counting as"Other".

OSX 10.11.6

Late 2013 rMBP with 512GB SSD.

Any ideas?