  We analyze two 3D general-relativistic magnetohydrodynamic accretion
simulations in the context of how they would manifest in Event Horizon
Telescope (EHT) observations of supermassive black holes. The two simulations
differ only in whether the initial angular momentum of the plasma is aligned
with the rapid (a = 0.9) spin of the black hole. Both have low net magnetic
flux. Ray tracing is employed to generate resolved images of the synchrotron
emission. When using parameters appropriate for Sgr A* and assuming a viewing
angle aligned with the black hole spin, we find the most prominent difference
is that the central shadow in the image is noticeably eccentric in tilted
models, with the ring of emission relatively unchanged. Applying this procedure
to M87 with a viewing angle based on the large-scale jet, we find that adding
tilt increases the angular size of the ring for fixed black hole mass and
distance, while at the same time increasing the number of bright spots in the
image. Our findings illustrate observable features that can distinguish tilted
from aligned flows. They also show that tilted models can be viable for M87,
and that not accounting for tilt can bias inferences of physical parameters.
Future modeling of horizon-scale observations should account for potential
angular momentum misalignment, which is likely generic at the low accretion
rates appropriate for EHT targets.
