A phone that is right for artist's studio (7)
I believe the answer is:
Here is my best explanation:
'artist's studio' is the definition.
(I've seen this before)
'a phone that is right' is the subsidiary indication.
'phone' becomes 'tel'.
'that is' becomes 'ie' ('i.e.' can be a synonym of 'that is').
'right' becomes 'r' (common abbreviation).
'for' is the link.
(Other definitions for atelier that I've seen before include "Workshop or artist's studio", "Tie earl up in the artist's place", "Designer's workshop", "I relate to workshop used by artist", "Artist's workroom", "Artist's workshop, studio" and "Artist's studio (French)".)