Your cat may either feel threatened, curious, excited or just asking for attention, lol that’s vague, so you’ll have to figure that out depending on other factors.

When cats feel threatened or scared, their instinct is to make themselves look bigger and more viscous to scare off their enemy, puffing off their fur, propping up their tails, and standing is their trick to look as big as possible.

They can also be standing to reach something they’re curious about (just stopped midway, so they’re just standing, haha it happens) or are excited and are preparing to jump.

They may also be extending their head to you so it’s easier for you to give them a head scratch, or they may be bunting (rubbing their head to give you their scent, making you theirs, haha) or just basically asking for attention.

You’ll need to observe your cat and their surrounding to know for sure – either way, a standing cat is a cute cat 😀