Site Stats Showing Visitors or Impressions?

In the last month, a relatively minor link that I put up has turned out to be my number two producer of traffic (after google, before msn).

Heres the question. Are these really unique visitors? Or could it be that my stats program (livestats.xsp) is reporting each time their page with my graphic on it (which is pulled from my site) is viewed?

Heres how they show it on their site (ie pulled realtime from mine)...




Heres the data - sort-of - from my reporting program.

Anybody know?

Report Description LiveStats.xsp
Report Description:
Referring Domains that Visitors came from during the week of Jan 8th, 2006
Report Range: Week of Jan 8th, 2006
Report Scope: Live Data (forecasted values)
List Size: 25 of 384
Activity Breakdown

www.google.com
www.thesiteinquestion.com
search.msn.com
search.yahoo.com
www.google.ca