Today I got into weird condition. I was doing Redirect for Sitecore item over IIS rewrite module. When I preview item from publish tab preview, it is redirecting properly. But when I preview item from presentation tab preview command it is not redirecting i.e. showing item presentation.
So there are two different preview behaviors for the same item, it strike me to think about difference between these two preview options.
- Under Publish tab: Preview Command
- Under Presentation tab: Preview Command
Please don't tell me that one preview mode open in new browser tab whereas second not :) , I am asking about feature wise difference.
Under Publish tab: only users with the relevant publishing roles/access can see this tab and have the ability to open a new window to preview in the context of the site (in a multi-site solution). This is likely often used and similar to Page Editor, without being able to actually edit.
Under Presentation tab: only users with the relevant designer roles/access can see this tab and have the ability to open a tab in the shell interface to simply preview the presentation layer. This is likely not used often as Page Editor is more likely to be used and almost the same thing as the mode above.
As Mark said, they will have different URLs possibly and query string params. I recommend you compare them to see if your re-write rules meets both.
Also, I have a blog post about this same issue when getting the context site. Although it's not 100% relevant, it does have code that shows what parameters you can expect in one mode vs. the other.