I find it funny that Uzu is also crying upon seeing the pictures. See what I did there? :D Actually, I'm surprised he's reacting to Gamagoori's picture.
Is this a joke on Satsuki and Ragyou's dominating brilliance making it difficult to get a proper picture?
You were right
Ah, Satsuki-sama! Do you have photos of yourself when you were little?This is new data.Is this someone else?Give it back!!Here, young miss. Looks funny.What the...he's amazingly adorable...What are you all doing?Yes, I do. Soroi. They're shining...! The entire Kiryuuin family shines too brightly...!
Each sentence ends with から (because), making the literal translation "Because they're shining...! Because the Kiryuuin family is shining...!" Basically, it implies that they can't see her too well because of all of the shining.