How to use: Dynamic loading
1. Insert the marker

Stretch the Dynamic load marker to cover the desired area of your drawing. Depending on further setup, this area will react to your mouse cursor or to a click.
2. Attach a document page

Choose the page that contains the drawing which should be dynamically loaded into the current page. Do it like if you were setting up a hyperlink - select the marker, press Ctrl+K and select the proper page from document contents list.
3. Choose the desired mode

Right-click the marker, and choose the first option (Mode: …). In the dropdown, select Load on mouseover or Load on click - whatever suits your goal. Press OK when you are done.
4. Mark the target location

Move the little yellow thingy around to mark where the upper-left corner of the dynamically loaded drawing should be placed.
WARNING:
This marker will work properly only when you apply the real-pixel-size hack to the page setup. This is done by switching the page metrics to points (pt), and it’s scale to 1 pt = 1,3333 pt. When you do so, all points sizes reported by Microsoft Visio™ will actually match almost accurately the pixel sizes of the same drawing exported to a webpage.