Either he is tiny or everything else is giant

Jack looked around the room, it was definitely his sisters old room how he remembered seeing it, the feminine décor pastel colours pinks, purples and light blues of the walls. Her bed in the middle of the room rather than against the wall, a very womanly choice of arrangement.

Jack estimated by the size of the giant bed he must have been maybe not much more than an inch or two tall now if that. The fact he was now so small without knowing why scared him and he was starting to hear loud thuds from somewhere. He became increasingly more terrified as he realised he was no longer on the ground, something had picked him off the floor a tight grip on him and was walking towards the bed which he noticed had his sisters laptop and some kind of books laying spread over the duvet. Wriggling to a position he could see more he turned his head to see his now giant sister with massive grin on her face.

"Oh Jackie I'm so glad I found you, I was beginning to think I lost you for a second when I made you smaller, but it's ok now. Now you can help me with what I wanted to do" she said as she lay down on her bed with her laptop and all her books?