Scraping only for missing art?

[A_La_Derp]

Forgive my ignorance here but I am new. If I have art for the majority of my collection, with only a few things missing. Will scraping art from thegamesdb.net scrape art for all roms in the romlist or only for those that can't find existing local art?

If it does scrape for all roms in the romlist, will any local art in the directory that AM is pointed to supersede the scraped art?

[hermine.potter]

Just tested a few monents ago:

Scrape artwork for 40 rom-files: 5 seconds (40 files(s) downloaded)

delete one of the artworks and scrape again : 1 second (1 file(s) downloaded)

replaced an existing artwork with another artwork (which has nothing to do with the game) : 1 second (0 file(s) downloaded)

Seems that AM only replace missing files (and not existing).