If the GLAM gift shop has actually purchased the original visual artworks from the artist, this is the initial sale, and when the GLAM gift shop sells the item to their customer this is a resale which will be regarded as a qualifying resale, assuming the other criteria are met.
If however, the artist has instead consigned the original visual artworks to the GLAM gift shop to sell on their behalf, then there has not yet been any sale or transfer of ownership as ownership remains with the artist, in which case when the GLAM gift shop sells the original visual artwork to their customer it will be the first sale rather than a qualifying resale and no reporting or royalty will be required.