You can try below things to improve performance of page:
1. Use [Dianoga][1] tool for optimize images.
[1]: https://github.com/kamsar/Dianoga
2. You can use jQuery lazy loader plugin.
3. Set height and width parameters on image
4. Apply cache on component
- Use Dianoga tool for optimize images, you can read more about it on this link.
- You can use jQuery lazy loader plugin.
- Apply Sitecore cache on component.
- Set height and width parameters on image.
You can refer this link as well to get more information Get Optimized Image in sitecore