Deborah said it very well for me, and viva too. I am a people-watcher and love just the mere act of taking it all in, enjoying the parade of humanity.
But I also confess to having ulterior motives. When pressed for time, I check out the outfits of participants who share some aesthetic or style preference with me, so I can get ideas and inspiration. But I also make it a point to check out the WIWs of those who have very different styles from mine. I appreciate it all.
Beautifully shot photos are wonderful (Aida rocks in this department), and greatly appreciated, but I cut people a lot of slack in this department. I've been called out for posting crappy WIW photos even though I am a photographer by trade. But I've explained before that if I take a photo of my outfit, it's pretty much as I'm heading out the door, and getting involved with tripod, location, lighting, posing, image downloading and editing, etc, would send me very quickly down the rabbit-hole of perfectionism and would hinder me from ever posting an outfit. Quite honestly, I hate being the subject of a photo anyway, so I give big props to anyone who takes a photo of their outfit and shares it here.