Q:

Evaluation inside text cell returns InputForm output

I just have discovered that it is possible to incorporate calculation in a text cell (you can create a text cell by typing Alt+7) by highlighting the formula and typing Ctrl+Shilt+Enter, but in the following case the output is a ugly InputForm result. How can I get a good-looking 2D expression as the output?
 
Here is the formula
 \!\(
  \*SubsuperscriptBox[\(∫\), \(0\), \(t\)]\(
  \*SuperscriptBox[\(E\), \(\(-\ ρ\)\ s\)] \[DifferentialD]s\)\)

A:

Interesting. It turns out to be necessary to highlight the code after the cursor is moved into the embedded cell. Notice when the cursor is inside the embedded cell, the background is colored:

