Yup, they are. (Though I definitely have a few in my own albums, ha.) Oh, and that particular image seems okay to me, but generally it's safe to go by "If in doubt, leave it out", to save time/confusion/etc.
3nodding 

GUYS guys, I got the xxxHolic official guide yesterday, and the thing covertly ships DouWata, I swear. J-just, the two page guide to "Doumeki and Watanuki's Tale of friendship" and the boxouts that say things like "Hitsuzen: Watanuki wanted to give the last fondant ou Chocolat to Himawari, but Doumeki ate it instead. Perhaps his
hopeful connection with Himawari is not as deep as his
reluctant connection with Doumeki."