We report Magnetospheric MultiScale (MMS) observations of two electron vortices with a roughly 10 km or 2-3 electron skin depths cross-section across the magnetospheric separatrix of a dayside magnetopause reconnection. The enhanced electron vorticity, which is caused by a significant velocity shear in the electron flows streaming in opposite directions along northward-directed magnetic field lines, leads to perturbations perpendicular to the reconnecting magnetic field on the order of 1-2 nT. The high electron vorticity periods are also associated with electron phase space holes having the largest bipolar parallel electric field amplitudes $\sim$ 25 mV/m observed across this exhaust. Less intense $\sim$ 10 mV/m electron phase space holes propagate along a northward magnetic field away from the X-line within a northward reconnection exhaust. The electron phase space holes with the largest bipolar parallel electric fields are observed to propagate toward the X-line within discrete channels of southward and super-Alfv\’{e}nic 1500 km/s electron flows in the magnetospheric separatrix layer.