Time evolution of the Gaia16aye microlensing event, with the "data representation" on the left and more intuitive "geometric representation" on the right. The light curve (top left) shows how the source brightness has been changing during the event. Middle panel contains the one-dimensional (in the direction of Gaia scanning motion) offset of the light centroid from the reference position, along with residuals. Majority of the centroid motion is due to parallax and proper motion of the source star (blue model), but these two effects do not describe all the data properly. The impact of astrometric microlensing is relatively small, but clearly visible, especially on the residuals panel (bottom left), which shows both lensing (red) and non-lensing (blue) models, with respect to the data. The non-lensing model fails to reproduce the Gaia measurements especially during the caustic crossings, where the light centroid position changes vastly due to strong variations in the configuration of the source images. Since Gaia astrometry is one-dimensional, it is difficult to imagine the geometry of the event using only the astrometric data presented on the left. We reinforce the readers imagination with the right panel, which shows the trajectory of the source (dashed, blue line), the light centroid (red) and orbital motion of the lensing system, along with the caustic (dark gray) that gradually changes its shape and rotates due to the motion of the lens' components. Black filled circles mark epochs of Gaia astrometric measurements. Trajectories shown on the right panel are relative to the mass center of the lensing system. The light green vertical line on the left panels marks the ongoing epoch displayed on the right, to help indentifying what is happening during the event and navigate between the "data representation" and "geometric representation". For example, one can easily see the critical changes happening during caustic crossings - whenever the source trajectory intersects with the caustic, one can see the flux spike (top left panel), but also a stronger astrometric deviation (bottom left).