无法用php（yii 1）在kml描述上显示图像

i want to generate kml file using yii, the problem is, i want to add an image on snippet description using html tag but when it was generated, the image not show (broken), when i check the path, it works. why it happen? is kml description just support for text only? how i can add a picture on my snippet?

here is a screenshot :

thankyou in advance,