The Pinter photo is a very poor fake. There is an original of Dodgson, a self-portrait, where the image is flipped horizontally for the forgery. Ina Liddell claimed she was the true photographer of that Dodgson portrait.

The source of Alice's open mouthed kiss is from Dodgson's group shot of the three Liddell sisters in a tableau called "Open Your Mouth." Alice's mouth is open for the cherries that Ina is dangling.

As much as I'm sure Charles wanted such an event in his life, the image is what modern Photoshop equipped people WANT so that they can say he sure WAS a pedophile, and chastise him for it. Just look closely at Alice's hand on his neck. You'll see a sharp edge between her hand and the gray blur of the back ground. There are many other indicators in this one photo that it is a forgery. There are other, different photos, that are fakes, as well.

Was he a pedophile? Certainly. Did he have a physical relationship with Alice which caused the Dodgson/Liddell breakup? Probably not. The best guess, based on all the surrounding writings of the "missing pages", is that Alice's parents saw a nude photo of one of the girls.

https://i2.wp.com/www.bookofdaystales.com/wp-content/uploads/2016/01/lc2.jpg

https://www.alamy.com/stock-image-liddell-edith-lorina-alice-open-your-mouth-lewis-carroll-071860-163594383.html