Cats are guided heavily by their noses, which feature a phenomenal sense of smell. If an item has your scent, they love to be near it because it brings them joy. They feel safe and secure around said object. Cats are also territorial and will sit on your bag as a territory marking exercise.
So a kitty may like to go out "in a familiar space", "to look at new things" like birds, animals, trees and water or just cars and people passing by. My kitty loved the park so much when I took Her one time that She ran away to there for two days following. Naughty! She was seen being chased by a fox into a Neighbour's yard. OMG... Yes She came Home unscathed by Herself and no I did not spank Her, lol.
When Miss Pookii is in Her backpack, We only go on walks where She isn't jostled, and She agrees to go in the backpack. I let Her sit in it for a good ten to twenty minutes before We set off so She is well settled in there. Always add a toy or two or three. Remember - Cats like to be hidden sometimes. So if You can provide that for Them without Them having to search for it, that's going to be awesome for Their comfort.
Please don't ever let Your Pet sit in the sun for more than a couple of minutes. Always take a drinking bowl and water in case Your trip is extended past normal drinking times which, as an owner, You should know. Never leave Your Pet unattended. Constantly check on Your Pet's comfort.
As a caution I like to wear a special scent when taking Miss Pookii out, so if She gets lost She might be able to find Me and Home easier. The theory is that I would keep the doors open till She came Home, and keep on reapplying the scent. I could sprinkle it around Home as well, or add it to the oil burner. The scent I use is the Pheromone Perfume We sell. Cats are very tuned to that.
Most pheromones are detected by the sense of smell. However, not all smells are pheromones. Mammals, including humans, also give off a cloud of molecules that represent our unique individual "smell" or chemical profile. These differences between individuals make it possible for dog and cats to distinguish people by smell.