The Béla Theme uses the Image Panels module instead of a "Hero" image or slideshow. Image panels feature partially hidden images with text that expand and contract when hovered over.
Image panels are meant to just give a glimpse of the full image. Images panels aren't great if you need for the whole image to display.
You can use more or less images than the five that come with the Béla theme. When using fewer images, more of each image is visible.