Maybe it is, and then again maybe it's not...
I've checked out the original picture and the bathing suit picture...
It's quite possible that the pink top titties picture is an accurate representation of Avril's tits. Since she invariable wears a bra in most of her perfomances. I checked out pictures from about 10 different concerts, in all of them she's usually wearing a black bra, and the shoulder straps show up.
The bathing suit pictures depict her with a decent size B. Taking into account that a bra tends to compress the breast somewhat, the picture could be of Avril's tits.
So my final conclusion is that it might be Avril's tits, but I tend to think it isn't! For one thing, the picture of her singing is difficult to determine if it's actually Avril or a wanna-be, and the t-shirt looks a little shinier in the second picture, like it's a closer weave of cotton.
