Few more photos here, including Snow Queen holding the hat box.
The Sorcerer’s hat! (or Sorceress’ hat, as the case may be). So, why does the Snow Queen have the hat? I’m guessing her sisters, the Queen of Arendelle and Belle’s mother, wanted to remove Ingrid’s powers with that hat (hence the title “Family Business”). Elsa’s parents wanted to remove their daughter’s powers when they sought Rumple’s help, but couldn’t because he didn’t have the hat. The same threats may have been made against the Snow Queen by her family, which is why she really desires a family that loves her (surprise). Elsa’s and Belle’s mothers may have been in on it, which is why Belle and Elsa’s memories were erased. Prediction: Emma, Elsa, Anna, and Belle will eventually melt the Snow Queen’s frozen heart to become the family that loves her.
"That’s how you know you’ve really got a home. When you leave it, there’s this feeling that you can’t shake. You just miss it." Neal Cassidy