The phrase "unfavourable comparisons" means that something or someone is being compared to others in a negative way, and they are not appearing as good or desirable. Full definition
When we're in the throes of envy, we may fear that if we give voice to our feelings, it may cue others to draw unfavourable comparisons between our successful peers and us. (slaw.ca)
From its opening scene, the film willingly exposes itself to unfavourable comparison by opting to start at the exact same time and place as the critically acclaimed documentary. (lwlies.com)
Adding insult to injury, director Richard Loncraine invites unfavourable comparison to Woody Allen's Manhattan, casting, in Keaton, the same lead actress, and repeatedly shooting her and Freeman at what appears to be the same park bench, by the same bridge, utilised in Allen's far superior rom - com. (flicks.co.nz)