Hi Chris!
Just to translate the <code-speak> a bit for others that might read this thread in the future... ;^)
You can achieve this result within Muse by creating a text frame that is 100% browser width (drag the width of the text frame to snap to the left and right edges of the browser background are in Muse). Then take the sets of objects you want to have "reflow" and group each set. Then cut it, click an insertion point in the 100% width text frame and paste. At this point you have a group that will behave like a single letter/character in the text frame. Repeat this for each item you want to "reflow." You can use the text tool to select everything in the text frame and align center.
If you then Preview in Browser and resize the browser narrow enough the groups you've pasted into the text frame don't fit on one line, they'll wrap to two, three, etc. lines and the text frame they're in will grow in height, if necessary. You can also use paragraph indents to adjust the browser width at which the wrapping occurs.