I want to load a graphical frontend (in Adobe Flex) containing some labels with
text and an image dynamically from an HTTPservice connecting to a MySQL
database. For instance, the HTTPservice returns the following XML data;

<layout>
<element posX="200" poxY="400">
<label>Company</label>
<text>Some Company & Co</text>
</element>
<element posX="400" posY="400">
<label>CEO</label>
<text>Some name</text>
</element>
</layout>

Is this possible and what kind of approach/functions can I use to accomplish
this?

You need to parse the XML file with E4X, extract the information you need, add components of the relevant type with ActionScript and set their data.