shoes, boots
鞵 centers on footwear made from leather: shoes and boots. The two given meanings are direct applications of this core idea.
鞵 combines 革 (leather) with 奚, which likely contributes the sound. The character is a phono-semantic compound for leather footwear.
The left side 革 means leather, and the right side 奚 looks like a person with a big head and legs, like someone trying on a new pair of leather shoes. Picture a cobbler fitting leather boots onto a customer.
For アイ, imagine an eye (アイ) on the leather shoe, watching you as you put it on. The eye sound cues アイ while the shoe is made of leather.