Some default Mobile Optimised event templates will have a 'Sponsors' logo section that is responsive. The images within this section have been set to adjust to screen size.
Sponsors section on Monitor
Sponsors section on Mobile
Recommended Image Size: 639px wide, 369px high (minimum)
Your template will usually come with 4 Sponsor Logo placeholders in this section (if ALL placeholders are in use, see How to add another row of sponsor logos).
To replace an existing Sponsor Logo image,
1. Navigate to the Page Editor for the home page of the event
2. Right click on a Sponsor Logo icon. Select Image Properties
3. Upload or Browse server and select new image.
4. Once selected, remove the Width and Height values which have appeared. Click OK to insert.
5. The new sponsor logo has now been inserted. Save page, preview site.