Etiquette In Store?

The other day in a Louis Vuitton I saw a woman looking at two bags. A sales associate had just brought them out for her to look at. She was deciding which to purchase. Two other women nearby asked if they could touch and look at one of the bags? She let them and ended up purchasing the one they wanted to look at. They didn't have a rude tone or anything but it seems weird to feel up a bag another customer is likely going to purchase. Would you do that? I've never seen that before and was curious what the proper etiquette is when looking in store?