Most explanation methods for CLIP hand you one importance score per image patch and per word. FIXLIP also scores every pair, so you can see which word interacts with which part of the picture. These pairwise explanations rebuild CLIP's similarity score faithfully and beat the single-score methods GAME and Grad-ECLIP by a wide margin once more than one object is in the picture.
Evidence
correlational
Key metric
pointing game 0.83 / 0.81 / 0.83 / 0.85 for 1-4 objects (weighted Banzhaf, p = 0.7), versus GAME 0.61 / 0.43 / 0.33 / 0.28
Caveat
A rival pairwise method, exCLIP, scores higher still on the multi-object cases.