To Display the Images in Random, Add numbers as PostFix to the Names of the images like Image1, Image2..,
Then use the following code to display the images,

Aspx page,

Use one div to hold the image tag,

<div id="tipsBox">
<img alt="Keep the Look with all..." src="ImagePath/<%# tipsBox %>.jpg" />
</div>

C# Code Behind

Create the instance to the Random class,

Random randomTipsBox = new Random();
tipsBox +="Image"+ randomTipsBox.Next(1, 9);