  We consider 4d $\mathcal N=4$ $U(N)$ SYM and the leading giant graviton
correction to the Schur defect 2-point functions of $\frac{1}{2}$-BPS Wilson
lines in rank-$k$ symmetric and antisymmetric representations. We study in
particular the large $k$ limit for the symmetric case and the regime $1\ll k
\ll N$ in the antisymmetric one. We present exact results for the correction in
agreement with matrix model evaluation at finite $N,k$. The Wilson lines in
symmetric/antisymmetric representations admit a description in terms of
D3$_{k}$ and D5$_{k}$ brane probes representing a collection of $k$ fundamental
strings. In this picture, giant graviton corrections come from fluctuations of
brane probes in presence of a wrapped D3 brane giant graviton. In particular,
for the antisymmetric case, our leading correction matches the half-index of
the 3d $\mathcal N=4$ Maxwell theory living on the 3d disk which is a part of
the giant graviton divided out by the D5$_{k}$ probe, as recently proposed in
arXiv:2404.08302. For the symmetric case at large $k$, we derive an explicit
exact residue formula for the leading correction.
