Drawing Annotated Parse Tree for Syntax Directed Definition
The Dragon book style starts with the parse tree of the expression, i.e., the root (I think the very top is a mistake, the expression is an error as written) is the step $E \Rightarrow E + T$. The tree is then decorated giving the attributes their value (like $E.val = 19$). In an attributed grammar you give the grammar and the attributes, so that the grammar looks in part as (subindices mark diferent uses of the same symbol, left to right):
\begin{eqnarray}
E \rightarrow T \quad E.val \leftarrow T.val \\
E \rightarrow E + T \quad E_0.val \leftarrow E_1.val + T.val
\end{eqnarray}
You see that the answer to your second question is that the value of the child $F$ is used to compute the value of $T$.