  We analyze the quark-mass dependence of electromagnetic properties of two and
three-nucleon states. To that end, we apply the pionless effective field theory
to experimental data and numerical lattice calculations which simulate QCD at
pion masses of 450~MeV and 806~MeV.
  At the physical pion mass, we postdict the magnetic moment of helium-3,
$\mu_{^3He}=-2.13~$nNM, and the magnetic polarizability of deuterium,
$\beta_D=7.33~10^{-2}~$fm$^3$. Magnetic polarizabilities of helium-3,
$\beta_{^3He}=9.7~10^{-4}~$fm$^3$, and the triton,
$\beta_{^3H}=8.2~10^{-4}~$fm$^3$, are predictions.
  Postdictions of the effective theory for the magnetic moments are found
consistent with QCD simulations at 806~MeV pion mass while our EFT result
$\beta_D=2.92~10^{-2}~$fm$^3$ was not extracted from the lattice. The deuteron
would thus be relatively pliable compared to a three-nucleon state for which we
postdict $\beta_{^3H}=3.9~10^{-5}~$fm$^3$. At $m_\pi=450~$MeV, the magnetic
moment of the triton is predicted, $\mu_{^3He}=-2.15(5)~$nNM, based on a
conjecture of its binding energy, $B_{^3H}\cong 30$~MeV.
  For all three pion masses, we compare the point-charge radii of the two and
three-nucleon bound states. The sensitivity of the electromagnetic properties
to the Coulomb interaction between protons is studied in anticipation of
lattice calculations with dynamical QED.
