You know how when you upload a single Picture in a Photo Post, Tumblr makes it itty bitty on dashboards? (Kind of like this post)
You can fix that by using the Transparent Strip here. Yup. There’s a photo there. But it’s transparent! All you have to do is save it, and upload it as your second photo using the vertical layout (the default one when you upload 2 pictures). It won’t show up on dashboards or blogs, but it’ll make your single picture post larger on dashboards.
Just a little helpful hint for those interested :)