I haven't used MS-DIAL or mzmine2 enough to give you definite answers about the software.
However, I do see that the precursor masses are different between the two images. Not by much, but enough to suggest that they aren't showing the same DDA product scans. I assume this is why they differ i.e. they are showing different scans at different retention times -> different abundances of coeluting peaks.
If the software is showing the 'best product ion scans' that match a library, the difference would be in how they have implemented spectral similarity. There are many parameters that can be tuned and I guess the authors have settled on slightly different ones.
I hope that helps.