Custom shapes have been used in many visualisations I have looked at but I hadn't ever tried to import my own images before. That was until now... So how do you do it I hear you ask?
Well here's quick view. First, go and find 'My Tableau Repository' in your file structure. Here is the source of unlocking a lot of custom features in tableau (including bespoke colour palettes by using the 'Preferences' file).
Then, you simply create a new folder in the 'Shapes' folder. Call it what you like as this is what will appear in the custom shapes.
When creating your viz, simply click on the 'Shapes' part of the 'Marks Card' and then expand as follows:
So using the basketballs as a representation of the number of placings each country had shows that the US were not as dominant (especially at the World Championships) as one would expect.