If there is valuable software, database or other asset that is not currently contributing to the income - or will influence the earnings trend upwards - this could increase the price the site reaches at auction. Similarly, if there is an asset that will cease to exist after sale or a license that will revert or end post-sale this could adversely affect the price. If you haven't provided any of those figures then there may not be relevant notes to put this valuation in better context.
There is generally a far lower level of competition among buyers for sites providing free hosting/image hosting/other freebie services. That said, sites offering free hosting tend to go for higher multiples than those offering other freebie services. Paid services - from web design to logo creation - can reach higher multiples if all the work is outsourced.
The lower confidence level reflects that with service sites the multiples vary widely depending on the service offered. For example, site hosting services tend to go for higher multiples than free image hosting. The valuation provided here is a mid-figure and typical variations are from 2x to 24x
Web businesses currently available for sale at various forums