It sounds as if you are accessing your mail using Comcast webmail.
If this is the case:
Check under Preferences
, and make sure that Display HTML in the body of email
is checked under choose how to display email messages containing HTML.
I'm also going to direct you to the Comcast help forums. Those forums are provided to Comcast customers, and are a great resource for vendor specific issues. There are forums for computer issues, email issues, security, internet, cable tv, and CDV.
Many times we, the users there, can provide answers tech support and customer service can't.
Click the link below, you'll be sent to the sign in page. Log in with your Comcast user ID (the part before .net) and your password. You will next see a first time forum users page, asking you to choose a screen name for use in the forums. Once you set that up, you'll be taken to the actual forums. http://forums.comcast.net/comcastsupport/
There have been many posts concerning embedded pictures in Comcast mail.
At the bottom of the forum page is a search function. You can search for other posts about this issue, but Webmail has been known to be flakey sometimes with showing a picture that is enbedded in an e-mail (not an attachment) If you do a search (bottom of every page) you will see many posts on it, but few solutions other than using a real e-mail client. Having said that, might be fixed tho when Smartzone is released (still stickie at top of the Email Forum in Comcast help forums)
If you do a search, when the results show, click on the words Date/Time to have the results show in chronological order newest to oldest.