解释下这段英语的意思,

问题描述:

解释下这段英语的意思,
Subject of your submission is already well covered in our data base and the image does not exceed in quality,composition and technique most images already online.- Lighting and composition are very important in creating a quality stock image with high sale potential.

您上传的内容已经被录入我们的数据库了,然而图片在质量,内容和技术并没有超过网上业已存在的图片.-光线和内容对创作高质量的具有高销售潜力的存备图片非常重要.