In case anyone is wondering: on page 53, Ash had an identical gym bag. And in the second panel on page 60, we can see that there are two bags in the room when Nikki is changing. In her rush to the gym she grabbed the wrong one.
BTW, there is a new Pita pic in the gallery as well as new fanart from andromedakun. Thanks Andro! 😛 Cheers -TK