Fresco seems to have trouble seeing what's currently in a Drive folder. I've dropped PSDs in a Drive folder to import it into Fresco, but the list available in Fresco appears to be days behind what's actually on Drive.
Is there a way to refresh it so that you can import files?
Fresco should be seeing whatever iOS is making available through its inter-app support. What do you see when you open the Google Drive app on your iPad? Can you share a screen shot showing Google Drive app view compared to Fresco's view? (They should be identical). Perhaps the files have not fully synced onto Google Drive yet?