In your photoshop example... that looks like a 12pt font size to me. your signature looks like a 10 to me. But remember bling... in browsers, people can change the font size. For example, I am looking at a website in IE. the font size they are using is "12 pt". When I go to the prefs>language/fonts, and change the font size setting... it makes everything bigger, even though the font size is still the "same". So your setting could be different than someone else's browser.
Can you understand that post, or is it kind of confusing?