Hi Courtenay! This is tricky because Google Ad sizes, for example, are different from screen sizes for mobile, tablet and desktop. Digital ads such as the ones in this tutorial are often placed on a website or mobile experience, whereas the multiple sizes tutorial I just made is for complete layouts. Does that make sense? As a Pro member, feel free to email me if you want further guidance.
I really want to combine this with your 'multiple sizes' tip--any thoughts on this?