Skye snaps her fingers and sparks flicker between them and crackle down her arm. Her hair stands on edge, and her eyes are wide. 

“That … that was something.”

Quote from Kol_Drake >>

"Think you can talk to the old lady's cat to find out what was going on?"

 

 Kylaski shakes her head, "No, not unless it's a talking cat. Floating eyes are usually smarter."

Xaul clicks his tongue and says ‘I could have done that previously, but traded that ability away for a boon to help this little rascal!’, whilst tickling Barnacle under the ‘chin’ to cheer him up 

Xaul clicks his tongue and says ‘I could have done that previously, but traded that ability away for a boon to help this little rascal!’, whilst tickling Barnacle under the ‘chin’ to cheer him up 

Kylaski starts looking around for a kitty...

Damros calls forth his Unseen Servant 
and commands it to start picking up things and placing them back on shelves or counter tops.

"An hour of picking up is halved with help..."

Once the cat realises the threat has gone, it emerges from its hiding place. It is currently on the second floor, probably having stealthily moved back once the gazer left. 

With a dc12 insight check, you can deduce based on the mewing of the gazer, the thing it was searching for was the cat. Just the cat was a much better hider than the gazer was seeker. 

Is the cat wearing a collar, or is there any other obvious sign of what the gazer wanted the cat for? Did the cat emerge from a hole we saw, or something that might contain treasure?

The cat has a collar. It's nothing special but does confirm the cat belongs to Uza. Nothing special about the hiding place either. The cat does look quite plump but otherwise a standard cat. 

Kylaski comments, "We may never know why the gazer was looking so intently for that cat. It might have been for a snack, or something else. If for a snack, why so persistent? Maybe the cat intruded somewhere the gazer was protecting and it chased after the cat. I doubt the cat knows even if we could talk to it."

Xaul will know (from having one as a familiar) thay gazers are not very intelligent (int score of 3). So it's highly plausible that a hungry gazer gets a bit hangry and fixates on a specific snack. And the more it eluded them, the angrier (and more determined) they got. 

Equally it's plausible that the cat is really a druid in wildshape and the gazer caught them smuggling something from the Xanathar (seeing as the last time you met a gazer that wasn't Barnacle, it was guarding a gazer sewer).

Based on options I've seen discussed, you may make theories but you will not have a concrete answer. But at the end of the day, you have held up your end of the bargain for Mirt. 

"Other than tidying up... is there anything else we can do beside 'report back' to the shop owner?  Who is going to explain the ramshackle remains of her wares?"

Kylaski asks, "What's to explain? She locked an aberration into her store, and it tore the store apart looking for her cat. Can't say she made a mistake there, if she had stayed, it might have decided she was easier prey. Or not, since we don't know why it was after the cat."

"True that..."  Damros says softly as he directs his Unseen Servant to the last bit of chaos to pick up.

"I suppose we should go back to Felzoun's Folly and let Dame Uza Solizeph know her shop is 'safe' but tossed about," Damros said slowly. 

"Perhaps a brief stop to quench our thirst and then on to that other shop, Weirdbottle’s Concoctions... to get that potion?"

Skye puts one hand on Damros’ shoulder and for a moment, perhaps, it feels almost like she is offering support, or perhaps even offering to take his place in dealing with the harridan in human form. 

Then she roughly pushes him a step forward and turns herself to the side to get herself a quart of ale from the tavern owner before they head out on their next mission. 

Sehaethas steps forward, "i can handle this."

{Once the excitement was over, Kylaski gave Sehaethas control again. Which may be confusing too Uza, since she hasn't seen Sehaethas.

Approaching Uza, Sehaethas says, "I've got some good news and bad news for you. The ball of eyes has been destroyed. And although it was searching for your cat, your cat is fine. The bad news is that in the process of searching for your cat, the ball of eyes made a mess of your shop, throwing most of the stuff on shelves onto the floor, with some of it breaking."

Xaul makes a conscious effort to keep Barnacle hidden on the party's return, and lingers behind the party whilst they let Uza know the job has been done.