Throughout most of the Batman Comic Issue #15’s, there is an ongoing theme. The theme is the Joker who will be crossing over to all the Batman-related comics. For each Issue #15 comic book, there is an interesting piece that shows up a lot such as the Joker card. However, there are two Batman-related comic books that do not show the Joker card but something else. Batgirl #15 and Teen Titans #15 show a double sided mirrored card of the main characters, Batgirl and Red Robin. See below:
Is this a coincidence? Probably not, since DC Comics is all about marketing. However, which artist drew this first? Brett Booth (artist of Teen Titans) answers this question:
Apparently DC liked my cover to Teen Titans 15 so much they use the idea twice!
— Brett Booth (@Demonpuppy) September 14, 2012
It’s very weird to see Batgirl on the opposite side of the Joker as a bride, which contributes to the deranged world of the Joker. Really, you can’t understand the reason behind Batgirl #15’s cover art. It looks like they just kinda did for the effect. However, Brett Booth’s cover art shows more meaning. What that meaning might be, we’ll just have to find out in December.
Source- DC Comics