Set on Fire

It is recommended that the depth of the image (3D) to be within the comfortable limits of eye convergence for each viewer. That is, the closest element in the image should not force the eye to look too close, and the farthest element should not force the eye to look away. Parallel looking is equivalent to looking at the furthest possible point, the Moon for example, or the stars.
Some people can look slightly divergent without undue effort, but this should not be abused.

For the maximum recommended screen sizes I have taken into account the situation where the maximum gap for the most distant elements in the image does not exceed ~7 cm, i.e. I have taken as reference an interpupillary distance of ~7 cm. Medium and large screens are viewed from a reasonably large distance so that slight deviations from the calculations can be tolerated.
So the stereoscopic window is the plane of the screen, which is easy to view being located at a reasonable distance, and the farthest element requires a parallel view for comfortable viewing.
The calculations I made were based on the position of the closest elements placed in the plane of the screen, so they do not violate the stereoscopic window.

You can actually measure the width of the image observed on the screen (for one eye!) adjusted so that the stereoscopic window is not crossed and you can also measure the distance between the furthest points in the image, for the two eyes.

In the case of the image taken by you, corrected so as not to violate the stereoscopic window, displayed on the screen at a width of ~50cm (for one eye), the offset between the furthest objects is ~2.8cm. For an inter-eye distance of 7cm, results 7:2.8=2.5. So the 50cm wide image can be enlarged to ~50x2.5=~125cm wide, so that the offset of the farthest points reaches 7cm=the interpupillary distance taken as an example, resulting in a parallel view.

The entire depth range can be brought forward by breaking the stereoscopic window (this procedure is used in cinema projections), and the image may contain elements far in front of the stereoscopic window, which may not be intersected because of their location, etc...

I work for some projects involving VR, in which case it has to be calculated in advance how all the elements of the image should be placed in depth, so that the viewer's gaze is not forced, regardless of personal interpupillary distance.🙂