Slam is only 50% of course but all was good. What was East thinking?
East didn’t want to get distracted by the ♦Q and figured A/K/K or A/A were required. Hence the kontrol ask. When West showed 3 kontrols, East reassessed, noting that ♣K and ♥AQ would be fine. Hence 4♦. 4♠ was pleasing, suggesting ♥AQ & ♣K.