Left: SPHERE image of the disk surrounding HD 100453. The image presents the polarimetric intensity in the R-band. Indicated are also the ellipse of the outer disk (from Benisty et al. 2017) and the position angle of the line connecting the shadows. Right: the derived inclination and position angle for the inner disk surrounding HD 100453 as a function of the assumed height of the scattering surface on the outer disk, h. The purple coloured regions indicate where we expect the height of the outer disk to be using models of the spectral energy distribution. The orange regions indicate the values for θ₁ and φ₁ given the uncertainties as defined in the text. The red horizontal bars indicate the values for θ₁ and φ₁ (with error bars) as derived from interferometric observations (Lazareff et al. 2017).