Hi Nelson,
The gap is caused by the overflow:auto CSS property that I added so that overly big images will still be viewable by using a scrollbar. Seems that this change may not be worth it.
I will remove it on the next update, but in the mean time, you can remove it yourself by deleting lines 431 – 433 in style.css.
These are the lines that you need to delete:
.entry-content p, .entry-content ol, .entry-content ul{
overflow:auto;
}