Not wanting to make things awkward but please don't, showers struggle at the best of times as they tend not to have the best fall built into the waste run. Flexi pipes under those circumstance can sag, that then causes issues with flow and restrictions as debris can then sit in the depression. ideally a way should be found to make it rigid pipe. I see it's a linear drain, is where it is sitting its final location on those joists?
The other slight concern may also be that I can see the 40mm waste is running against the joists, is this an upstairs bathroom and are those joists structural, or downstairs and sitting on supports on crete? You need to be careful, a joist supporting a suspended floor should only be notched an 1/8th of its depth. Obviously say a 50mm notch to take a 46mm ABS waste pipe is well beyond that. If it's the latter then not so bad, just make sure any notched areas have a support piece in line, directly below the notch, at least 200mm either side. If it upstairs then it's not ideal.
